Indirect Direct Troffer Luminaire

ABSTRACT

An illumination system is described including a plurality of illumination devices, each device including (i) light-emitting elements (LEEs) arranged along a corresponding first axis; (ii) an optical extractor extending along a corresponding longitudinal axis parallel to the first axis; and (iii) a light guide positioned to receive at a first end of the light guide light emitted by the LEEs and guide it to a second end of the light guide. The optical extractor is optically coupled to the light guide at the second end and is shaped to redirect the light guided by the light guide into a range of angles on either side of the light guide. The illumination devices are connected to each other to form a polygon such that the longitudinal axes of the connected illumination devices lie in a common plane.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/570,243, entitled “Illumination Devices Including Multiple LightEmitting Elements,” filed on Aug. 8, 2013, which is acontinuation-in-part of U.S. patent application Ser. No. 13/205,548,entitled “Solid-State Luminaire,” filed on Aug. 8, 2011, and also claimsbenefit of the following provisional applications: ProvisionalApplication No. 61/594,849, entitled “Hollow Optical Flux Manifold andLuminaire Based Thereon,” filed on Feb. 3, 2012; Provisional ApplicationNo. 61/594,954, entitled “Solid-State Luminaire,” filed on Feb. 3, 2012;Provisional Application No. 61/603,205, entitled “Solid-StateLuminaire,” filed on Feb. 24, 2012; and Provisional Application No.61/640,719, entitled “Luminaire,” filed on Apr. 30, 2012. The entirecontents of each of these priority applications are hereby incorporatedby reference.

BACKGROUND

Light sources are used in a variety of applications, such as providinggeneral illumination and providing light for electronic displays (e.g.,LCDs). Historically, incandescent light sources have been widely usedfor general illumination purposes. Incandescent light sources producelight by heating a filament wire to a high temperature until it glows.The hot filament is protected from oxidation in the air with a glassenclosure that is filled with inert gas or evacuated. Incandescent lightsources are gradually being replaced in many applications by other typesof electric lights, such as fluorescent lamps, compact fluorescent lamps(CFL), cold cathode fluorescent lamps (CCFL), high-intensity dischargelamps, and light-emitting diodes (LEDs).

SUMMARY

A variety of luminaires (also referred to as illumination devices) aredisclosed that are configured to manipulate light provided by one ormore light-emitting elements (LEEs). In general, embodiments of theluminaires feature one or more optical couplers (e.g., parabolicreflectors) that redirect illumination from the LEEs to a reflectorwhich then directs the light into a range of angles. The opticalcouplers can be referred to interchangeably as primary optics or opticalcollectors. In some embodiments, the luminaire includes a secondreflector that reflects at least some of the light from the firstreflector. In certain embodiments, the luminaire includes a light guidethat guides light from the optical coupler to the first reflector. Thecomponents of the luminaire can be configured in a variety of ways so avariety of intensity distributions can be output by the luminaire. Suchluminaires can be configured to provide light for particular lightingapplications, including office lighting, task lighting, cabinetlighting, garage lighting, wall wash, stack lighting, and down-lighting.

Among other advantages, embodiments of the luminaires can provideinexpensive illumination solutions with highly uniform illumination andchromaticity, also referred to as color, in ranges of angles tailoredfor specific lighting applications.

In one aspect, an illumination device includes a substrate having firstand second opposing surfaces, such that each of the first and secondsurfaces are elongated and have a longitudinal dimension and atransverse dimension shorter than the longitudinal dimension; aplurality of light-emitting elements (LEE) arranged on the first surfaceof the substrate and distributed along the longitudinal dimension, suchthat the LEEs emit, during operation, light in a first angular rangewith respect to a normal to the first surface of the substrate; one ormore solid primary optics arranged in an elongated configuration alongthe longitudinal dimension of the first surface and coupled with theLEEs, the one or more solid primary optics being shaped to redirectlight received from the LEEs in the first angular range, and to providethe redirected light in a second angular range, a divergence of thesecond angular range being smaller than a divergence of the firstangular range at least in a plane perpendicular to the longitudinaldimension of the first surface of the substrate; a solid light guidecomprising input and output ends, the input and output ends of the solidlight guide being elongated in the longitudinal dimension and havingsubstantially the same shape, where the input end of the solid lightguide is coupled to the one or more solid primary optics to receive thelight provided by the solid primary optic in the second angular range,and the solid light guide is shaped to guide the light received from thesolid primary optic in the second angular range and to provide theguided light in substantially the same second angular range with respectto the first surface of the substrate at the output end of the solidlight guide; and a solid secondary optic comprising an input end, aredirecting surface opposing the input end and first and second outputsurfaces, such that each of the input end, and redirecting, first outputand second output surfaces of the solid secondary optic are elongatedalong the longitudinal dimension. The input end of the solid secondaryoptic is coupled to the output end of the solid light guide to receivethe light provided by the solid light guide in the second angular range.The redirecting surface has first and second portions that reflect thelight received at the input end of the solid secondary optic in thesecond angular range, and provide the reflected light in third andfourth angular ranges with respect to the normal to the first surface ofthe substrate towards the first and second output surfaces,respectively, where at least prevalent directions of propagation oflight in the third and fourth angular ranges are different from eachother and from a prevalent direction of propagation of light in thesecond angular range at least perpendicular to the longitudinaldimension of the first surface of the substrate. The first outputsurface is shaped to refract the light provided by the first portion ofthe redirecting surface in the third angular range as first refractedlight, and to output the first refracted light in a fifth angular rangewith respect to the normal to the first surface of the substrate outsidethe first output surface of the solid secondary optic, and the secondoutput surface is shaped to refract the light provided by the secondportion of the redirecting surface in the fourth angular range as secondrefracted light, and to output the second refracted light in a sixthangular range with respect to the normal of the first surface of thesubstrate outside the second output surface of the solid secondaryoptic.

The foregoing and other embodiments can each optionally include one ormore of the following features, alone or in combination. Theillumination device can further include a tertiary optic including afirst reflector elongated along the longitudinal dimension, the firstreflector at least in part facing the first output surface of the solidsecondary optic, wherein the first reflector is shaped to reflect atleast some of the light output by the first output surface of the solidsecondary optic in the fifth angular range as first reflected light in aseventh angular range with respect to the normal to the first surface ofthe substrate, wherein at least a prevalent direction of propagation oflight of the seventh angular range is different from a prevalentdirection of propagation of light of the fifth angular range at least ina plane perpendicular to the longitudinal dimension, such that a firstportion of the intensity distribution output by the illumination deviceduring operation includes at least some of the first reflected light.The first reflector can be coupled to an edge of the first outputsurface of the solid secondary optic, and at least a portion of thefirst reflector is an involute of at least a portion of the first outputsurface of the solid secondary optic. The tertiary optic can furtherinclude a second reflector elongated along the longitudinal dimension,the second reflector facing the second output surface of the solidsecondary optic, wherein the second reflector is shaped to reflect atleast some of the light output by the second output surface of the solidsecondary optic in the sixth angular range as second reflected light inan eight angular range with respect to the normal to the first surfaceof the substrate, wherein at least a prevalent direction of propagationof light of the eight angular range is different from a prevalentdirection of propagation of light of the sixth angular range at least ina plane perpendicular to the longitudinal dimension, such that the firstportion of the intensity distribution output by the illumination deviceduring operation includes at least some of the second reflected light.

In some implementations, the first and second reflectors at least inpart transmit at least some of the light output by the first and secondoutput surfaces of the solid secondary optic in the fifth and sixthangular ranges, respectively, wherein a second portion of the intensitydistribution output by the illumination device during operation includesthe transmitted light. The first and second reflectors haveperforations, the perforations being positioned to transmit at leastsome of the light output by the first and second output surfaces of thesolid secondary optic in the fifth and sixth angular ranges,respectively, wherein the second portion of the intensity distributionoutput by the illumination device during operation includes thetransmitted light.

In some implementations, a first parameter combination can include (i) ashape of the one or more primary optics, (ii) a shape of the firstportion of the redirecting surface and an orientation thereof relativeto the input end of the solid secondary optic, (iii) a shape of thefirst output surface and an orientation thereof relative to the firstportion of the redirecting surface, and (iv) a configuration of thelight guide, the first parameter combination determining the fifthangular range, wherein the first parameter combination is tailored suchthat the fifth angular range matches a predefined fifth angular range; asecond parameter combination can include (v) the shape of the one ormore primary optics, (vi) a shape of the second portion of theredirecting surface and an orientation thereof relative to the input endof the solid secondary optic, (vii) a shape of the second output surfaceand an orientation thereof relative to the first portion of theredirecting surface, and (viii) the configuration of the light guide,the second parameter combination determining the sixth angular range,wherein the second parameter combination is tailored such that the sixthangular range matches a predefined sixth angular range, and a relativeoffset of the first and second portions of the redirecting surface withrespect to the input end of the solid secondary optic determines arelative distribution of light between the fifth angular range and thesixth angular range, wherein the relative offset is selected such thatthe relative distribution matches a predefined relative distribution.

In some implementations, the first parameter combination further caninclude an intensity distribution of light provided by the one or moreLEEs within the first angular range, the second parameter combinationfurther comprises the intensity distribution of light provided by theone or more LEEs within the first angular range. The illumination deviceof claim 7, can further include a tertiary optic comprising: a reflectorelongated along the longitudinal dimension, the reflector at least inpart facing the first output surface of the solid secondary optic,wherein the reflector reflects at least some of the light output by thefirst output surface of the solid secondary optic in the predefinedfifth angular range as first reflected light in a seventh angular rangewith respect to the normal to the first surface of the substrate,wherein at least a prevalent direction of propagation of light of theseventh angular range is different from a prevalent direction ofpropagation of light of the predefined fifth angular range at least in aplane perpendicular to the longitudinal dimension, such that a firstportion of the intensity distribution output by the illumination deviceduring operation includes the first reflected light, and a secondportion of the intensity distribution output by the illumination deviceduring operation includes at least some of the light output by thesecond output surface of the solid secondary optic within the predefinedsixth angular range, wherein the intensity distribution is asymmetricwith respect to the first portion and the second portion.

In some implementations, a system can include N such illuminationdevices, where N is an even number larger or equal to 4, the Nillumination devices being connected to each other to form a polygon,such that the substrates of the connected illumination devices lie in acommon plane, and any of pair-wise parallel illumination devices fromamong the connected illumination devices outputs the first portion ofthe intensity distribution towards each other, and the second portion ofthe intensity distribution away from each other. N can be a numberlarger or equal to 3, the N illumination devices arranged such that thesubstrates of the illumination devices are substantially coplanar, andeach one of the illumination devices can output the first portion of theintensity distribution towards one or more opposite ones of theillumination devices, and emits the second portion of the intensitydistribution away from each other. In some implementations, N can be oddnumber.

In some implementations, at least one of the input end, the redirectingsurface, and the first and second output surfaces of the solid secondaryoptic has a uniform cross-sectional shape perpendicular to thelongitudinal dimension of the first surface of the substrate. In someimplementations, for a cross-sectional plane perpendicular to thelongitudinal dimension of the first surface of the substrate, theredirecting surface has an apex that separates the first and secondportions of the redirecting surface. In some implementations, for across-sectional plane perpendicular to the longitudinal dimension of thefirst surface of the substrate, the redirecting surface is shaped as anarc of a circle, and the first and second portions of the redirectingsurface represent first and second portions of the arc of the circle. Insome implementations, for a cross-sectional plane perpendicular to thelongitudinal dimension of the first surface of the substrate, either ofthe first and second portions of the redirecting surface has one or moreapexes. In some implementations, for a cross-sectional planeperpendicular to the longitudinal dimension of the first surface of thesubstrate, the first portion of the redirecting surface is shaped as aplurality of potentially disjoint, piecewise differentiable firstcurves, and the second portion of the redirecting surface is shaped as aplurality of potentially disjoint, piecewise differentiable secondcurves.

In some implementations, the plurality of LEEs and the one or more solidprimary optics are integrally formed. In some implementations, the oneor more solid primary optics, the solid light guide and the solidsecondary optic are integrally formed of one or more transparentmaterials, and the one or more transparent materials have substantiallymatching refractive indices.

An angular range includes (i) a divergence of the angular range and (ii)a prevalent direction of propagation of light in the angular range,wherein the prevalent direction of propagation corresponds to adirection along which a portion of an intensity distribution has amaximum, and the divergence corresponds to a solid angle outside ofwhich the intensity distribution drops below a predefined fraction ofthe maximum of the intensity distribution.

In another aspect, an illumination device includes one or morelight-emitting elements (LEEs) operatively disposed on one or moresubstrates and configured to emit light in a first angular range; one ormore primary optics optically coupled with the one or more LEEs andconfigured to direct light received from the one or more LEEs in thefirst angular range at one or more input ends of the one or more primaryoptics, and provide directed light in a second angular range at one ormore output ends of the one or more primary optics, a divergence of thesecond angular range being smaller than a divergence of the firstangular range; a light guide optically coupled at an input end of thelight guide with the one or more output ends of the one or more primaryoptics, the light guide shaped to guide light received from the one ormore primary optics in the second angular range to an output end of thelight guide and provide guided light in substantially the same secondangular range at the output end of the light guide; and a solidsecondary optic optically coupled with the second end of the light guideat an input end of the solid secondary optic to receive light from thelight guide, the solid secondary optic having a redirecting surfacespaced from the input end of the solid secondary optic and an outputsurface, the redirecting surface configured to reflect light received atthe input end of the solid secondary optic in the second angular rangeand provide the reflected light in a third angular range towards theoutput surface, the output surface extending between the input end andthe redirecting surface, the output surface being shaped to refract thelight provided by the redirecting surface in the third angular range asrefracted light and to output the refracted light in a fourth angularrange outside the output surface of the solid secondary optic, the solidsecondary optic having an elongated configuration to provide the fourthangular range with a longitudinal extension and a shorter, transverseextension.

The foregoing and other embodiments can each optionally include one ormore of the following features, alone or in combination. In someimplementations, the illumination device can further comprise a secondredirecting surface and a second output surface, the second redirectingsurface spaced from the input end of the solid secondary optic andconfigured to reflect light received at the input end of the solidsecondary optic in the second angular range and provide the reflectedlight in a fifth angular range towards the second output surface, thesecond output surface extending between the input end and the secondredirecting surface, the second output surface being shaped to refractthe light provided by the second redirecting surface in the fifthangular range as refracted light in a sixth angular range outside thesecond output surface of the solid secondary optic, the elongatedconfiguration of the solid secondary optic configured to provide thesixth angular range with a longitudinal dimension. In someimplementations, the illumination device can further comprise anelongated first reflector optic facing the output surface and arrangedalong the longitudinal extension of the fourth angular range, whereinthe first reflector optic is shaped to reflect at least some of thelight output by the output surface of the solid secondary optic in thefourth angular range as first reflected light, and to provide the firstreflected light in a seventh angular range, wherein the seventh angularrange is different than the fourth angular range.

In some implementations, the elongated first reflector optic is spacedapart from the output surface. In some implementations, the illuminationdevice can further comprise an elongated second reflector optic facingthe second output surface and arranged along the longitudinal extensionof the sixth angular range, wherein the second reflector optic is shapedto reflect at least some of the light output by the second outputsurface of the solid secondary optic in the sixth angular range assecond reflected light, and to provide the second reflected light in aneight angular range, wherein the eighth angular range is different thanthe sixth angular range. The elongated second reflector optic can bespaced apart from the second output surface.

In some implementations, the one or more substrates include oneintegrally formed, elongated substrate. In some implementations, the oneor more substrates include a plurality of substrates, the plurality ofsubstrates having an elongated configuration. In some implementations,one or more of the LEEs and one or more of the primary optics areintegrally formed. In some implementations, the one or more primaryoptics include one integrally formed, elongated primary optic. In someimplementations, the one or more primary optics include a plurality ofprimary optics, the plurality of primary optics having an elongatedconfiguration. In some implementations, the one or more primary opticsare configured as one or more solid primary optics and the light guideis configured as a solid light guide. In some implementations, the oneor more solid primary optics, the solid light guide and the solidsecondary optic are integrally formed of one or more transparentmaterials, and the one or more transparent materials have substantiallymatching refractive indices.

In some implementations, the illumination device can further comprise areflective layer disposed on the redirecting surface of the solidsecondary optic. In some implementations, the redirecting surface of thesolid secondary optic is configured to reflect at least some of thelight received at the input end of the solid secondary optic in thesecond angular range via total internal reflection. The longitudinalextension of the fourth angular range is perpendicular to a prevalentdirection of propagation of light emitted by the one or more LEEs in thefirst angular range. In some implementations, a shape of the input endof the light guide matches a shape of the output end of the one or moreprimary optics. In some implementations, a shape of the input end of thesolid secondary optic matches a shape of the output end of the lightguide.

In one aspect, an illumination device includes a substrate having firstand second opposing surfaces, such that each of the first and secondsurfaces are elongated and have a longitudinal dimension and atransverse dimension shorter than the longitudinal dimension; aplurality of light-emitting elements (LEE) arranged on the first surfaceof the substrate and distributed along the longitudinal dimension, suchthat the LEEs emit, during operation, light in a first angular rangewith respect to a normal to the first surface of the substrate; one ormore primary optics arranged in an elongated configuration along thelongitudinal dimension of the first surface and coupled with the LEEs,the one or more primary optics being shaped to redirect light receivedfrom the LEEs in the first angular range, and to provide the redirectedlight in a second angular range, a divergence of the second angularrange being smaller than a divergence of the first angular range atleast in a plane perpendicular to the longitudinal dimension of thefirst surface of the substrate; a secondary optic comprising aredirecting surface elongated along the longitudinal dimension, theredirecting surface of the secondary optic being spaced apart from andfacing the one or more of the primary optics, wherein the first andsecond portions of the redirecting surface reflect light received fromthe one or more primary optics in the second angular range, and providethe reflected light in third and fourth angular ranges with respect tothe normal to the first surface of the substrate, respectively, whereinat least prevalent directions of the third and fourth angular ranges aredifferent from each other and from a prevalent direction of propagationof light of the second angular range at least perpendicular to thelongitudinal dimension of the first surface of the substrate; and atertiary optic comprising a first reflector elongated along thelongitudinal dimension, the first reflector optic being spaced apartfrom and facing the first portion of the redirecting surface of thesecondary optic, wherein the first reflector is shaped to reflect atleast some of the light provided by the first portion of the redirectingsurface of the secondary optic in the third angular range with respectto the normal of the first surface of the substrate as first reflectedlight in a fifth angular range with respect to the normal to the firstsurface of the substrate, wherein the fifth angular range is differentthan the third angular range, such that a first portion of an intensitydistribution output by the illumination device during operation includesat least some of the first reflected light.

The foregoing and other embodiments can each optionally include one ormore of the following features, alone or in combination. A secondportion of the intensity distribution output by the illumination deviceduring operation includes at least some of the light provided by thesecond portion of the redirecting surface of the secondary optic withinthe fourth angular range. In some implementations, the tertiary opticcan further include a second reflector elongated along the longitudinaldimension, the second reflector being spaced apart from and facing thesecond portion of the redirecting surface of the secondary optic,wherein the second reflector optic is shaped to reflect at least some ofthe light provided by the second portion of the redirecting surface ofthe secondary optic in the fourth angular range as second reflectedlight, and to provide the second reflected light in a sixth angularrange with respect to the normal to the first surface of the substrate,wherein the sixth angular range is different than the fourth angularrange, such that the first portion of the intensity distribution outputby the illumination device during operation includes at least some ofthe second reflected light. In some implementations, at least one of thefirst and second reflectors is thermally coupled with the substrate. Insome implementations, the one or more primary optics are configured asone or more solid primary optics. In some implementations, the first andsecond reflectors at least in part transmit at least some of the lightreceived from the redirecting surface, wherein a second portion of theintensity distribution output by the illumination device duringoperation includes the transmitted light. In some implementations, thefirst and second reflectors have perforations configured to provide thetransmitted light. In some implementations, the first and secondreflectors are arranged to have partial overlap with the fourth andsixth angular ranges, such that a second portion of the intensitydistribution output by the illumination device during operation includesat least some of the light provided by the first and second redirectingsurfaces that passes the first and second reflectors without beingreflected.

A first parameter combination can include (i) an intensity distributionof light provided by the one or more LEEs within the first angularrange, (ii) a shape of the one or more primary optics, and (iii) a shapeof the first portion of the redirecting surface and an orientationthereof, the first parameter combination determining the fifth angularrange, wherein the first parameter combination is tailored such that thefifth angular range matches a predefined fifth angular range; a secondparameter combination comprises (iv) an intensity distribution of lightprovided by the one or more LEEs within the first angular range, (v) ashape of the one or more primary optics, and (vi) a shape of the secondportion of the redirecting surface and an orientation thereof, thesecond parameter combination determining the sixth angular range,wherein the second parameter combination is tailored such that the sixthangular range matches a predefined sixth angular range, and a relativeoffset of the first and second portions of the redirecting surface withrespect to the second angular range determines a relative distributionof light between the fifth angular range and the sixth angular range,wherein the relative offset is selected such that the relativedistribution matches a predefined relative distribution.

In some implementations, a first portion of the intensity distributionoutput by the illumination device during operation includes the firstreflected light, and a second portion of the intensity distributionoutput by the illumination device during operation includes at leastsome of the light reflected from the second redirecting surface, whereinthe intensity distribution is asymmetric with respect to the firstportion and the second portion. In some implementations, at least one ofthe first and second reflector comprises a curved portion and asubstantially planar portion. In some implementations, a system caninclude N such illumination devices, where N is a number larger or equalto 3, the N illumination devices arranged such that the substrates ofthe illumination devices are substantially coplanar, and each one of theillumination devices outputs the first portion of the intensitydistribution towards one or more opposite ones of the illuminationdevices, and emits the second portion of the intensity distribution awayfrom each other. In some implementations, N can be an odd number. E.g.,N equals 4.

In some implementations, the tertiary optics of the illumination devicescomprise a common reflector. In some implementations, the redirectingsurface comprises a reflective material, where the reflective materialincludes one or more of Ag or Al. In some implementations, the secondaryoptic has a uniform cross-sectional shape along the longitudinaldimension of the first surface of the substrate. In someimplementations, at least one of the first and second portions of theredirecting surface has a uniform cross-sectional shape perpendicular tothe longitudinal dimension of the first surface of the substrate.

In some implementations, for a cross-sectional plane perpendicular tothe longitudinal dimension of the first surface of the substrate, theredirecting surface has an apex that separates the first and secondportions of the redirecting surface. In some implementations, the apexof the redirecting surface is a rounded vertex with a non-zero radius ofcurvature. In some implementations, the first and second portions of theredirecting surface have first and second arcuate shapes in thecross-sectional plane perpendicular to the longitudinal dimension of thefirst surface of the substrate. In some implementations, the first andsecond portions of the redirecting surface have one or more first andsecond linear shapes in the cross-sectional plane perpendicular to thelongitudinal dimension of the first surface of the substrate, such thatthe apex has a v-shape in the cross-sectional plane. In someimplementations, for a cross-sectional plane perpendicular to thelongitudinal dimension of the first surface of the substrate, theredirecting surface is shaped as an arc of a circle, and the first andsecond portions of the redirecting surface represent first and secondportions of the arc of the circle. In some implementations, the firstand second portions of the redirecting surface are separated, at leastin part, by a slot, and for a cross-sectional plane perpendicular to thelongitudinal dimension of the first surface of the substrate thatintersects the slot, first and second curves corresponding to the firstand second portions of the redirecting surface are separated by adiscontinuity.

In some implementations, at least portions of the first and secondportions of the redirecting surface partially transmit light. In someimplementations, either of the first and second portions of theredirecting surface comprise one or more slots, and for across-sectional plane perpendicular to the longitudinal dimension of thefirst surface of the substrate that intersects the one or more slots,first and second curves corresponding to the first and second portionsof the redirecting surface comprise one or more discontinuitiesassociated with the one or more slots. In some implementations, for across-sectional plane perpendicular to the longitudinal dimension of thefirst surface of the substrate, either of the first and second portionsof the redirecting surface has one or more apexes. In someimplementations, for a cross-sectional plane perpendicular to thelongitudinal dimension of the first surface of the substrate, the firstportion of the redirecting surface is shaped as a plurality ofpotentially disjoint, piecewise differentiable first curves, and thesecond portion of the redirecting surface is shaped as a plurality ofpotentially disjoint, piecewise differentiable second curves.

In some implementations, the substrate is integrally formed. In someimplementations, the substrate comprises a plurality of substrate tilesdistributed in an elongated configuration, each of the substrate tilescorresponding to one or more of the plurality of LEEs. In someimplementations, the one or more solid primary optics comprise oneintegrally formed, elongated primary optic. In some implementations, theone or more primary optics comprise a plurality of primary optics, theplurality of primary optics distributed in an elongated configuration.In some implementations, the plurality of LEEs and the one or moreprimary optics are integrally formed.

An angular range comprises (i) a divergence of the angular range and(ii) a prevalent direction of propagation of light in the angular range,wherein the prevalent direction of propagation corresponds to adirection along which a portion of an intensity distribution has amaximum, and the divergence corresponds to a solid angle outside ofwhich the intensity distribution drops below a predefined fraction ofthe maximum of the intensity distribution. In some implementations, thepredefined fraction is 5%.

In one aspect, an illumination device includes one or morelight-emitting elements (LEEs) operatively disposed on one or moresubstrates and configured to emit light in a first angular range; one ormore primary optics optically coupled with the one or more LEEs andconfigured to direct light received from the one or more LEEs in thefirst angular range and provide directed light in a second angularrange, the second angular range being smaller than the first angularrange; and a secondary optic spaced apart from the one or more primaryoptics and arranged to receive light from the one or more primary opticsin the second angular range, the secondary optic having a redirectingsurface configured to reflect light received from the one or moreprimary optics in the second angular range and provide the reflectedlight in a third angular range, the third angular range being differentfrom the second angular range, the secondary optic having an elongatedconfiguration to provide the third angular range with a longitudinalextension and a shorter, transverse extension.

The foregoing and other embodiments can each optionally include one ormore of the following features, alone or in combination. In someimplementations, the illumination device can further include a secondredirecting surface, the second redirecting surface configured toreflect light received from the one or more primary optics in the secondangular range and provide the reflected light in a fourth angular range,the fourth angular range being different from the second angular rangeand the third angular range, the elongated configuration of thesecondary optic configured to provide the fourth angular range with alongitudinal extension. In some implementations, the illumination devicecan further include an elongated first reflector optic being spacedapart from and facing the redirecting surface and arranged along thelongitudinal extension of the third angular range, wherein the firstreflector optic is shaped to reflect at least some of the light receivedfrom the redirecting surface in the third angular range as firstreflected light, and to provide the first reflected light in a fifthangular range, wherein the fifth angular range is different than thethird angular range at least perpendicular to the longitudinal extensionof the third angular range. In some implementations, the illuminationdevice can further include an elongated second reflector optic beingspaced apart from and facing the redirecting surface and arranged alongthe longitudinal extension of the fourth angular range, wherein thesecond reflector optic is shaped to reflect at least some of the lightreceived from the second redirecting surface in the fourth angular rangeas second reflected light, and to provide the second reflected light ina sixth angular range, wherein the sixth angular range is different thanthe fourth angular range at least perpendicular to the longitudinalextension of the fourth angular range.

In some implementations, the one or more substrates include oneintegrally formed, elongated substrate. In some implementations, the oneor more substrates include a plurality of substrates, the plurality ofsubstrates having an elongated configuration. In some implementations,one or more of the LEEs and one or more of the primary optics areintegrally formed. In some implementations, the one or more primaryoptics include one integrally formed, elongated primary optic. In someimplementations, the one or more primary optics include a plurality ofprimary optics, the plurality of primary optics having an elongatedconfiguration. In some implementations, the one or more primary opticsare configured as one or more solid primary optics. In someimplementations, the longitudinal extension of the third angular rangeis perpendicular to a prevalent direction of propagation of lightemitted by the one or more LEEs in the first angular range.

In one aspect, an illumination device includes one or morelight-emitting elements (LEEs) operatively disposed on a first surfaceof a substrate and configured to emit light in a first angular range;one or more primary optics optically coupled with the one or more LEEsand configured to direct light received from the one or more LEEs in thefirst angular range and provide directed light in a second angular rangewith respect to the first surface of the substrate, the second angularrange being smaller than the first angular range; a secondary opticspaced apart from the one or more primary optics and arranged to receivelight from the one or more primary optics in the second angular range,the secondary optic having a redirecting surface having and apex facingthe one or more primary optics and configured to reflect light receivedfrom the one or more primary optics in the second angular range andprovide the reflected light in a third angular range with respect to thefirst surface of the substrate, the third angular range being differentfrom the second angular range, the secondary optic defining an opticalaxis through the apex; and a reflector optic spaced apart from andfacing the redirecting surface, the reflector optic shaped to reflect atleast some of the light received from the redirecting surface in thethird angular range as first reflected light, and to provide the firstreflected light in a fifth angular range with respect to the firstsurface of the substrate, wherein the fifth angular range is differentthan the third angular range at least within a sectional plane throughthe optical axis.

The foregoing and other embodiments can each optionally include one ormore of the following features, alone or in combination. In someimplementations, the secondary optic has rotational symmetry about theoptical axis through the apex. In some implementations, one or morecross sections of at least a portion of at least one of the primaryoptics, the secondary optic and the reflector optic comprise a pluralityof at least one of a straight and an arcuate portion. In someimplementations, the one or more cross sections form an N-sided polygon.E.g., N is an odd number. In some implementations, the polygon is aregular polygon. In some implementations, the one or more cross sectionsrefer to planes perpendicular to the optical axis of the secondaryoptic. In some implementations, the one or more cross sections refer toplanes parallel to the optical axis of the secondary optic. In someimplementations, one or more of the LEEs, one or more of the primaryoptics, and the reflector optic have rotational symmetry about theoptical axis of the secondary optic. In some implementations, therotational symmetry is a discrete rotational symmetry. In someimplementations, the rotational symmetry of the secondary optic is adiscrete rotational symmetry. In some implementations, one or more ofthe LEEs, one or more of the primary optics, the secondary optic and thereflector optic are asymmetric with respect to the optical axis of thesecondary optic.

In some implementations, a parameter combination comprises (i) a shapeof the one or more primary optics, (ii) a shape of the redirectingsurface and an orientation thereof relative to the one or more primaryoptics, and (iii) an intensity distribution of light provided by the oneor more LEEs within the first angular range; the parameter combinationdetermining the third angular range, wherein the parameter combinationis tailored such that the third angular range matches a predefined thirdangular range. In some implementations, a relative offset of one or moreof the LEEs, one or more of the primary optics, and the secondary opticwith respect to one or more of one or more of the LEEs, one or more ofthe primary optics, and the secondary optic determines an asymmetry ofthe third angular range, wherein the relative offset is selected suchthat the asymmetry of the third angular range matches a predefinedasymmetry. In some implementations, the one or more LEEs provide anasymmetric first angular range and the parameter combination is tailoredto provide a substantially asymmetric predefined third angular range. Insome implementations, the one or more LEEs provide a substantiallysymmetric first angular range and the parameter combination is tailoredto provide a substantially asymmetric predefined third angular range.

In some implementations, a first portion of the intensity distributionoutput by the illumination device during operation includes at leastsome of the first reflected light. In some implementations, thereflector optic at least in part transmits at least some of the lightreceived from the redirecting surface, wherein a second portion of theintensity distribution output by the illumination device duringoperation includes the transmitted light. In some implementations, thefirst and second reflectors have perforations configured to provide thetransmitted light. In some implementations, the reflector optic isarranged to have partial overlap with the third angular range, such thata second portion of the intensity distribution output by theillumination device during operation includes at least some of the lightprovided by the redirecting surfaces that passes the reflector opticwithout being reflected. In some implementations, the redirectingsurface comprises a reflective material, where the reflective materialincludes one or more of Ag or Al.

In some implementations, the apex of the redirecting surface is arounded vertex with a non-zero radius of curvature. In someimplementations, the redirecting surface has one or more linear shapesin one or more cross-sectional planes through the optical axis of thesecondary optic. In some implementations, the redirecting surface isshaped as arcs of a circle. In some implementations, the redirectingsurface includes an opening. In some implementations, at least portionsthe redirecting surface partially transmit light. In someimplementations, for a cross-sectional plane the redirecting surface isshaped as a plurality of potentially disjoint, piecewise differentiablecurves. In some implementations, the substrate is integrally formed. insome implementations, the substrate comprises a plurality of substratetiles distributed in an elongated configuration, each of the substratetiles corresponding to one or more of the LEEs. In some implementations,the one or more primary optics are integrally formed. In someimplementations, the one or more LEEs and the one or more primary opticsare integrally formed.

An angular range comprises (i) a divergence of the angular range and(ii) a prevalent direction of propagation of light in the angular range,wherein the prevalent direction of propagation corresponds to adirection along which a portion of an intensity distribution has amaximum, and the divergence corresponds to a solid angle outside ofwhich the intensity distribution drops below a predefined fraction ofthe maximum of the intensity distribution. E.g., the predefined fractionis 5%.

In one aspect, an illumination device includes one or morelight-emitting elements (LEEs) operatively disposed on a substrate 3476and configured to emit light in a first angular range with respect to anormal to a first surface of the substrate; one or more primary opticsoptically coupled with the one or more LEEs and configured to directlight received from the one or more LEEs in the first angular range atone or more input ends of the one or more primary optics, and providedirected light in a second angular range at one or more output ends ofthe one or more primary optics, a divergence of the second angular rangebeing smaller than a divergence of the first angular range; a lightguide optically coupled at an input end of the light guide with the oneor more output ends of the one or more primary optics, the light guideshaped to guide light received from the one or more primary optics inthe second angular range to an output end of the light guide and provideguided light in substantially the same second angular range with respectto the first surface of the substrate at the output end of the lightguide; and a secondary optic optically coupled with the second end ofthe light guide at an input end of the secondary optic to receive lightfrom the light guide, the secondary optic having a redirecting surfacespaced from the input end of the secondary optic and an output surface,the redirecting surface having an apex facing the input end of thesecondary optic and configured to reflect light received at the inputend of the secondary optic in the second angular range and provide thereflected light in a third angular range with respect to the normal tothe first surface of the substrate towards the output surface, theoutput surface shaped to refract the light provided by the redirectingsurface in the third angular range as refracted light and to output therefracted light in a fourth angular range with respect to the normal tothe first surface of the substrate outside the output surface of thesecondary optic, the secondary optic defining an optical axis throughthe apex; wherein the one or more primary optics, the light guide andthe secondary optic are integrally formed of a transparent material.

The foregoing and other embodiments can each optionally include one ormore of the following features, alone or in combination. In someimplementations, the secondary optic has rotational symmetry about theoptical axis through the apex. In some implementations, the illuminationdevice can further include a reflector optic facing the output surface,the reflector optic shaped to reflect at least some of the light outputby the output surface of the secondary optic in the fourth angular rangeas first reflected light, and to provide the first reflected light in afifth angular range with respect to the normal to the first surface ofthe substrate, wherein the fifth angular range is different than thefourth angular range.

In some implementations, one or more cross sections of at least aportion of at least one of the primary optics, the light guide, thesecondary optic and the reflector optic comprise a plurality of at leastone of a straight and an arcuate portion. In some implementations, theone or more cross sections form an N-sided polygon. E.g., N is an oddnumber. In some implementations, the polygon is a regular polygon. Insome implementations, the one or more cross sections refer to planesperpendicular to the optical axis of the secondary optic. In someimplementations, the one or more cross sections refer to planes parallelto the optical axis of the secondary optic. In some implementations, oneor more of the LEEs, one or more of the primary optics, the light guideand the reflector optic have rotational symmetry about the optical axisof the secondary optic. In some implementations, the rotational symmetryis a discrete rotational symmetry. In some implementations, therotational symmetry of the secondary optic is a discrete rotationalsymmetry. In some implementations, one or more of the LEEs, one or moreof the primary optics, the secondary optic and the reflector optic areasymmetric with respect to the optical axis of the secondary optic. Insome implementations, at least a portion of at least one of the primaryoptics, the light guide, the secondary optic and the reflector optic hasa uniform cross section along an extension of the corresponding portion.

A parameter combination comprises (i) a shape of the one or more primaryoptics, (ii) a shape of the redirecting surface and an orientationthereof relative to the input end of the secondary optic, (iii) a shapeof the output surface and an orientation thereof relative to theredirecting surface, (iv) a configuration of the light guide, and (v) anintensity distribution of light provided by the one or more LEEs withinthe first angular range; the parameter combination determining thefourth angular range, wherein the parameter combination is tailored suchthat the fourth angular range matches a predefined fourth angular range.In some implementations, a relative offset of one or more of the LEEs,one or more of the primary optics, the light guide, and the secondaryoptic with respect to one or more of one or more of the LEEs, one ormore of the primary optics, the light guide and the secondary opticdetermines an asymmetry of the fourth angular range, wherein therelative offset is selected such that the asymmetry of the fourthangular range matches a predefined asymmetry.

In some implementations, the one or more LEEs provide an asymmetricfirst angular range and the parameter combination is tailored to providea substantially asymmetric predefined fourth angular range. In someimplementations, the one or more LEEs provide a substantially symmetricfirst angular range and the parameter combination is tailored to providea substantially asymmetric predefined fourth angular range. In someimplementations, the reflector optic is spaced apart from the outputsurface of the secondary optic. In some implementations, the reflectoroptic is coupled to an edge of the output surface of the secondaryoptic, and at least a portion of the reflector optic is an involute ofat least a portion of the output surface of the solid secondary opticwith respect to at least one cross section of the illumination devicethrough the optical axis. In some implementations, a first portion ofthe intensity distribution output by the illumination device duringoperation includes at least some of the first reflected light. In someimplementations, the reflector optic at least in part transmits at leastsome of the light output by the output surface of the solid secondaryoptic in the fourth angular range, wherein a second portion of theintensity distribution output by the illumination device duringoperation includes the transmitted light. In some implementations, thereflector optic has perforations, the perforations being positioned totransmit at least some of the light output by the output surface of thesolid secondary optic in the fourth angular range, wherein the secondportion of the intensity distribution output by the illumination deviceduring operation includes the transmitted light. In someimplementations, the reflector optic includes one or more transparentportions, the one or more transparent portions being positioned totransmit at least some of the light output by the output surface of thesolid secondary optic in the fourth angular range, wherein the secondportion of the intensity distribution output by the illumination deviceduring operation includes the transmitted light. In someimplementations, the reflector optic is arranged to have partial overlapwith the fourth angular range, such that a second portion of theintensity distribution output by the illumination device duringoperation includes at least some of the light output by the outputsurface of the solid secondary optic within the fourth angular rangethat passes the reflector optic without being reflected.

In some implementations, the reflector optic is thermally coupled withthe substrate. In some implementations, the redirecting surfacecomprises a reflective material, where the reflective material includesone or more of Ag or Al. In some implementations, apex of theredirecting surface is a rounded vertex with a non-zero radius ofcurvature. In some implementations, the redirecting surface has arcuateshapes in a cross-sectional plane parallel to the optical axis of thesecondary optic. In some implementations, the redirecting surface haslinear shapes in a cross-sectional plane parallel to the optical axis,such that the apex has a v-shape in the cross-sectional plane. In someimplementations, for a cross-sectional plane parallel to the opticalaxis of the secondary optic, the redirecting surface is shaped as an arcof a circle. In some implementations, the redirecting surface has anopening. In some implementations, at least portions of the redirectingsurface partially transmit light. In some implementations, In someimplementations, for a cross-sectional plane through the optical axis ofthe secondary optic, the first portion of the redirecting surface isshaped as a plurality of potentially disjoint, piecewise differentiablefirst curves.

In some implementations, the substrate is integrally formed. In someimplementations, the substrate comprises a plurality of substrate tiles.In some implementations, one or more primary optics are integrallyformed. In some implementations, the one or more LEEs and the one ormore primary optics are integrally formed.

An angular range comprises (i) a divergence of the angular range and(ii) a prevalent direction of propagation of light in the angular range,wherein the prevalent direction of propagation corresponds to adirection along which a portion of an intensity distribution has amaximum, and the divergence corresponds to a solid angle outside ofwhich the intensity distribution drops below a predefined fraction ofthe maximum of the intensity distribution. The predefined fraction canbe 5%.

In one aspect, an illumination device includes a substrate having firstand second opposing surfaces, such that each of the first and secondsurfaces are elongated and have a longitudinal dimension and atransverse dimension shorter than the longitudinal dimension; aplurality of light-emitting elements (LEE) arranged on the first surfaceof the substrate and distributed along the longitudinal dimension, suchthat the LEEs emit, during operation, light in a first angular rangewith respect to a normal to the first surface of the substrate; one ormore primary optics arranged in an elongated configuration along thelongitudinal dimension of the first surface and coupled with the LEEs,the one or more primary optics being shaped to redirect light receivedfrom the LEEs in the first angular range, and to provide the redirectedlight in a second angular range, a divergence of the second angularrange being smaller than a divergence of the first angular range atleast in a plane perpendicular to the longitudinal dimension of thefirst surface of the substrate; and a secondary optic comprising areflector optic elongated along the longitudinal dimension, thereflector optic being spaced apart from and facing the one or moreprimary optics, wherein the reflector optic is shaped to reflect atleast some of the light provided by the one or more primary optics inthe second angular range as reflected light in a third angular rangewith respect to the normal to the first surface of the substrate,wherein the third angular range is different than the second angularrange, such that at least some of the reflected light represents a firstportion of the intensity distribution output by the illumination deviceduring operation.

The foregoing and other embodiments can each optionally include one ormore of the following features, alone or in combination. In someimplementations, the one or more primary optics comprises one integrallyformed primary optic.

In one aspect, a luminaire includes at least one light-emitting diode(LED); a light guide including two opposing planar surfaces bothextending from a first end to a second end, the light guide beingpositioned to receive at the first end light emitted by thelight-emitting diode and guide it between the planar surfaces to thesecond end; and an optical extractor optically coupled to the lightguide at the second end, the optical extractor including a first opticalinterface and a second optical interface, the first optical interfacebeing positioned to reflect light exiting the light guide and the secondoptical interface being configured to transmit light reflected by thefirst optical interface.

The foregoing and other embodiments can each optionally include one ormore of the following features, alone or in combination. In someimplementations, the at least one LED includes a plurality of LEDsarranged in a row. In some implementations, each of the at least one LEDcan have substantially the same emission spectrum. In someimplementations, each of the at least one LED can emit white lightduring operation. In some implementations, at least some of the at leastone LED can be colored LEDs. In some implementations, at least some ofthe at least one LED can be blue, violet, or ultra-violet LEDs.

In some implementations, the luminaire can include a wavelengthconversion material positioned remote from the at least one LED in apath of light emitted by the at least one LED, the wavelength conversionmaterial being arranged to convert at least some of the light from theat least one LED into light of a longer wavelength. In someimplementations, at least one LED can have a nominal power in a rangefrom 0.1 W to 2 W.

In some implementations, the luminaire can include an optical elementpositioned to receive light emitted from the at least one LED andredirect the light to the first end of the light guide. In someimplementations, the optical element can include at least one opticalinterface shaped to collimate the light in at least one dimension. Forexample, the at least one optical interface of the optical element isshaped to collimate the light in two dimensions. As another example, theat least one optical interface of the optical element has a paraboliccross-sectional profile. As another example, the optical element isoptically coupled to the first end of the light guide. As anotherexample, the optical element is integrally-formed with the light guide.

In some implementations, the opposing planar surfaces of the light guidecan be parallel. In some implementations, the light guide can be formedfrom a dielectric material. In some implementations, the light guide canbe a rectangular piece of dielectric material having a length, a width,and a thickness, where the width corresponds to the dimension of therectangle between the first and second ends, the thickness correspondsto the dimension between the opposing planar surfaces, and the lengthcorresponds to the dimension orthogonal to the width and the thickness,the length being larger than the width and the thickness. For example,the width is larger than the thickness. The thickness can be 1 cm orless, for instance. As another example, the dielectric material is anorganic polymer. As another example, the organic polymer is acrylic. Asanother example, the dielectric material is an inorganic glass.

In some implementations, for a cross-sectional plane, the first opticalinterface can have a shape that includes a vertex. For example, theoptical extractor has a uniform cross-sectional shape along an axisextending orthogonal to the cross-sectional plane. As another example,the first optical interface includes a first planar portion and a secondplanar portion that meet at an edge corresponding to the vertex in thecross-sectional plane. Further, planar light guide surfaces can bearranged symmetrically about a notional plane extending between thefirst and second ends and the edge of the first optical interface liesin the notional plane. Furthermore, the first and second planar portionscan be arranged symmetrically with respect to notional plane. Also, thefirst and second planar portions can be arranged asymmetrically withrespect to the notional plane.

In some implementations, the first optical interface of the opticalextractor can have a v-shape in the cross-sectional plane. In someimplementations, the second interface has a portion having an arcuateshape in the cross-sectional plane. The arcuate portion can have aconstant radius of curvature.

In some implementations, the optical extractor can include a portionformed from a dielectric material, where a first surface of the portioncorresponds to the first optical interface and a second surface of theportion corresponds to the second optical interface. In someimplementations, the optical extractor can include a portion formed froma second material adjacent to the first surface, the first opticalinterface being the interface between the portion of the second materialand the portion of the dielectric material. For example, the secondmaterial is a reflective material. As another example, the secondmaterial is a metal. For instance, the metal can be aluminum.

In some implementations, the optical extractor can include a cylindricalelement having a cylinder axis and a wedge-shaped groove extending alonga cylinder axis. For example, the cylindrical element is formed from adielectric material and the optical extractor further includes a secondmaterial disposed on the surfaces of the wedge-shaped groove to for thefirst optical interface. As another example, the surface of thewedge-shaped groove is the first optical interface and the cylindricalsurface of the cylindrical element is the second optical interface.

In some implementations, the light guide can be optically coupled to theoptical extractor. In some implementations, the light guide can beintegrally-formed with the optical extractor. In some implementations,for a cross-sectional plane, the first optical interface has a firstarcuate shape and the second optical interface has a second arcuateshape. In some implementations, the optical extractor can have a uniformcross-sectional shape along an axis extending orthogonal to thecross-sectional plane. In some implementations, the optical extractorcan extend beyond a first of the planar surfaces in the cross-sectionalplane in the direction normal to the first planar surface, but does notextend beyond the second planar surface in the direction normal to thesecond planar surface.

In some implementations, the optical element and optical extractor canbe shaped so that, in a first plane, the luminaire directs substantiallyall of the light into a range of solid angles from −45 degrees to 45degrees, where 0 degrees corresponds to a normal of a planar surface ofthe light guide. In some implementations, the optical element andoptical extractor can be shaped so that the luminaire asymmetricallydistributes the light about 0 degrees in the first plane. In someimplementations, the optical element and optical extractor can be shapedso that, in a second plane orthogonal to the first plane, the luminairedirects substantially all of the light into a range of solid angles from−45 degrees to 45 degrees, where 0 degrees corresponds to the normal ofthe planar surface of the light guide. In some implementations, for across-sectional plane, the second optical interface can have a shapethat is an arc of constant radius, R, and the first optical interface isdisposed within a notional circle of radius R/n concentric with the arc,where n is a refractive index of a material from which the opticalextractor is formed.

In some implementations, the luminaire can include a reflectorpositioned remote from the optical extractor and positioned to receiveat least some of the light transmitted by the second optical interface.The reflector can include a first portion and a second portion, thefirst and second portions extending on opposing sides of the lightguide. Further, the first and second portions each can include a curvedsurface positioned to receive light transmitted by the second opticalinterface. Furthermore, in a cross-sectional plane, the curved surfacescan be concave in shape. Also, the curved surfaces can be specularlyreflecting surfaces. Further, the first and second portions can beperforated, the perforations being positioned to transmit at least someof the light transmitted by the second optical interface.

In some implementations, the optical element, optical extractor, andreflector can be shaped so that, in a first plane, the luminaire directsthe light into a range of solid angles substantially symmetrically about0 degrees, where 0 degrees corresponds to the direction extending fromthe first end of the light guide to the second end. In someimplementations, the optical element, optical extractor, and reflectorcan be shaped so that, in a first plane, the luminaire directs the lightinto a range of angles substantially asymmetrically about 0 degrees,where 0 degrees corresponds to the direction extending from the firstend of the light guide to the second end. In some implementations, theoptical element, optical extractor, and reflector can shaped so that, ina first plane, the luminaire directs at least some of the light into arange of angles from −45 degrees to 45 degrees, where 0 degreescorresponds to the direction extending from the first end of the lightguide to the second end. In some implementations, the optical element,optical extractor, and reflector can be shaped so that, in the firstplane, the luminaire directs substantially all of the light into therange of angles from −45 degrees to 45 degrees. In some implementations,the optical element, optical extractor, and reflector can be shaped sothat, in the first plane, the luminaire directs none of the light intoany angle from −90 degrees to −45 degrees and from 45 degrees to 90degrees. In some implementations, the optical element, opticalextractor, and reflector can be shaped so that, in the first plane, theluminaire directs at least some of the light into a range of angles from−110 degrees to −90 degrees and from 90 degrees to 110 degrees. In someimplementations, the optical element, optical extractor, and reflectorare shaped so that, in a first plane, the luminaire directs at leastsome of the light into a range of angles from −90 degrees to −45 degreesand from 45 degrees to 90 degrees, where 0 degrees corresponds to thedirection extending from the first end of the light guide to the secondend.

In some implementations, the optical element, optical extractor, andreflector can be shaped so that, in the first plane, the luminairedirects substantially all of the light into the range of angles from −90degrees to −45 degrees and from 45 degrees to 90 degrees. In someimplementations, the optical element, optical extractor, and reflectorare shaped so that, in the first plane, the luminaire is brightest in arange of angles from −75 degrees to −60 degrees and from 60 degrees to75 degrees.

In another aspect a method includes attaching the luminaire of claim 1to a ceiling and electrically connecting a power source to theluminaire. In some implementations, the ceiling is a ceiling of a roomin a building. In some implementations, the ceiling is a ceiling of agarage.

In another aspect a luminaire includes at least one light-emitting diode(LED); a light guide including two opposing surfaces both extending froma first end to a second end, the light guide being positioned to receiveat the first end light emitted by the light-emitting diode and guide itbetween the surfaces to the second end; a reflector; and an opticalextractor extending along a longitudinal axis orthogonal to a firstdirection between the first and second ends of the light guide, theoptical extractor being remote from the reflector and being opticallycoupled to the light guide at the second end, the optical extractorbeing arranged to redirect light exiting the light guide towards thereflector, where the optical extractor and reflector are shaped so that,in a first plane, the luminaire directs at least some of the light intoa first range of angles from −90 degrees to 90 degrees and directssubstantially none of the light into a second range of angles from −90degrees to 90 degrees, where 0 degrees corresponds to the firstdirection.

In another aspect, an illumination system includes a plurality ofluminaires, each luminaire including a plurality of light-emittingdiodes (LEDs) arranged along a corresponding first axis; an opticalextractor extending along a corresponding longitudinal axis parallel tothe first axis; and a light guide positioned to receive at a first endof the light guide light emitted by the light-emitting diodes and guideit to a second end of the light guide, where the optical extractor isoptically coupled to the light guide at the second end, the opticalextractor being shaped to redirect the light guided by the light guideinto a range of angles on either side of the light guide, and where theluminaires are connected to each other to form a polygon such that thelongitudinal axes of the connected modules lie in a common plane.

In some implementations, the polygon has a maximum dimension less than 2feet. In some implementations, the polygon is a quadrilateral. In someimplementations, the polygon includes four or more modules. In someimplementations, the optical extractor is shaped to redirect light intodifferent ranges of angles on opposing sides of the light guide. In someimplementations, the optical extractor includes a first opticalinterface positioned to receive the light from the light guide andreflect the light either side of the light guide. For example, for across-sectional plane, the first optical interface has a shape thatincludes a vertex.

In some implementations, the optical extractor can further include asecond optical interface positioned in the path of the light reflectedby the first optical interface and configured to transmit the light intothe range of angles. For a cross-sectional plane, the second interfacecan have a portion having an arcuate shape. The arcuate portion can havea constant radius of curvature.

In another aspect, a luminaire includes a plurality of light-emittingdiodes (LEDs) extending along a first axis; at least one collectorarranged to receive light emitted by the LEDs and redirect the light ina range of directions orthogonal to the first axis, at least partiallycollimating the light; a first reflective surface extending along alongitudinal axis parallel to the first axis, wherein the first axis andlongitudinal axis lie in a common plane and at least a portion of thereflective surface is positioned to receive the light from the at leastone collector and reflect the light into a range of angles on only oneside of the common plane.

In some implementations, the at least one collector includes a pluralityof collectors, each arranged to receive light emitted by a correspondingone of the plurality of LEDs. In some implementations, the at least onecollector includes at least one optical interface shaped to collimatethe light in at least one dimension. The at least one optical interfaceof the optical element can be shaped to collimate the light in twodimensions. In some implementations, for a cross-section, the at leastone optical interface of the optical element can have a parabolic shape.In some implementations, the at least one collector can include anelement formed from a solid dielectric material, the element beingarranged to transmit light from the LEDs towards the first reflectivesurface. For example, the at least one collector includes a reflectivesurface arranged to reflect light from the LEDs towards the firstreflective surface. As another example, the first reflective surface isa curved surface. The curved surface can be a concave surface. In someimplementations, the at least one collector and first reflective surfacecan be shaped so that the luminaire illuminates only the one side of thecommon plane.

In another aspect, an article includes a cabinet; and a luminaire asdescribed for the foregoing implementation mounted to a surface of thecabinet.

In another aspect, an article includes a piece of furniture having awork surface; the luminaire described above; and a mounting fixturearranged to position the luminaire to illuminate the work surface.

In another aspect, a luminaire includes at least one light-emittingdiode (LED) positioned at a first plane; a light guide including twoopposing surfaces both extending from a first end to a second end, wherethe first and second ends define a direction orthogonal to the firstplane and the light guide is positioned to receive at the first endlight emitted by the light-emitting diode and guide it between thesurfaces to the second end; a first surface positioned to reflect lightexiting the light guide into a range of angles towards the first plane;and a second surface arranged to extend through the range of angles andreflect at least some of the light reflected by the first surface awayfrom the first plane.

The term “optical axis” is used herein to refer to an imaginary linethat defines a path along or proximate which light propagates. Anoptical axis may correlate with one or more axes or planes of symmetryof components of an optical system or apparatus. A plurality of opticalaxes that refer to a planar or non-planar notional surface may bereferred to herein as an optical plane.

The term “rotational symmetry” is used herein, as the case may be, torefer to invariance under discrete or continuous rotation.

The terms “collimation” and “collimate” are used herein to refer to thedegree of alignment of rays of light or the act of increasing suchalignment including the reduction of divergence of the propagationdirections of a plurality of light rays, also referred to as a beam oflight, or simply light.

The term “light-emitting element” (LEE), also referred to as a lightemitter, is used to define any device that emits radiation in one ormore regions of the electromagnetic spectrum from among the visibleregion, the infrared region and/or the ultraviolet region, whenactivated. Activation of an LEE can be achieved by applying a potentialdifference across components of the LEE or passing a current throughcomponents of the LEE, for example. A light-emitting element can havemonochromatic, quasi-monochromatic, polychromatic or broadband spectralemission characteristics. Examples of light-emitting elements includesemiconductor, organic, polymer/polymeric light-emitting diodes, othermonochromatic, quasi-monochromatic or other light-emitting elements.Furthermore, the term light-emitting element is used to refer to thespecific device that emits the radiation, for example a LED die, and canequally be used to refer to a combination of the specific device thatemits the radiation (e.g., a LED die) together with a housing or packagewithin which the specific device or devices are placed. Examples oflight emitting elements include also lasers and more specificallysemiconductor lasers, such as vertical cavity surface emitting lasers(VCSELs) and edge emitting lasers. Further examples includesuperluminescent diodes and other superluminescent devices.

The term “light-converting material” (LCM), also referred to as“wavelength-conversion material” or phosphor is used herein to define amaterial that absorbs photons according to a first spectral distributionand emits photons according to a second spectral distribution. The termslight conversion, wavelength conversion and/or color conversion are usedaccordingly. Light-converting material may be referred to asphotoluminescent or color-converting material, for example.Light-converting materials may include photoluminescent substances,fluorescent substances, phosphors, quantum dots, semiconductor-basedoptical converters, or the like. Light-converting materials may includerare earth or other materials including, for example, Ce, Yt, Te, Eu andother rare earth elements, Ce:YAG, TAG, nitride, oxynitride, silicate,CdSe quantum dot material, AlInGaP quantum dot material. As used herein,an LCM is typically configured to generate longer wavelength light frompump light such as visible light or ultraviolet pump light, for example.Different LCM may have different first and/or second spectraldistributions.

As used herein, the term “optical interface” refers to the interfacebetween two materials having different optical properties. Examples ofoptical interfaces include a surface of an optical element (i.e., theinterface between the material forming the optical element and theambient atmosphere), the interface between adjacent optical elements,and the interface between an optical element and a coating disposed onthe elements surface.

As used herein, providing light in an “angular range” refers toproviding light that propagates in a prevalent direction and has adivergence with respect to the propagation direction. In this context,the term “prevalent direction of propagation” refers to a directionalong which a portion of an intensity distribution of the propagatinglight has a maximum. For example, the prevalent direction of propagationassociated with the angular range can be an orientation of a lobe of theintensity distribution. Also in this context, the term “divergence”refers to a solid angle outside of which the intensity distribution ofthe propagating light drops below a predefined fraction of a maximum ofthe intensity distribution. For example, the divergence associated withthe angular range can be the width of the lobe of the intensitydistribution. The predefined fraction can be 10%, 5%, 1%, or othervalues, depending on the lighting application.

As used herein, the term “about” refers to a +/−10% variation from thenominal value.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this technology belongs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an embodiment of a luminaire.

FIGS. 2A-2G show different aspects of a luminaire.

FIG. 3 is an intensity profile of an embodiment of a luminaire.

FIG. 4 is a schematic diagram showing aspects of a Weierstrassconfiguration.

FIG. 5 is a view of an embodiment of a luminaire.

FIG. 6 is a view of another embodiment of a luminaire.

FIG. 7 is a view of yet another embodiment of a luminaire.

FIG. 8 is a view of an embodiment of a troffer luminaire.

FIG. 9 is an intensity profile of an embodiment of a troffer luminaire.

FIGS. 10A-10C show aspects of an intensity distribution from an array oftroffer luminaires at a target surface.

FIGS. 11A and 11B are views of an embodiment of a pendant luminaire.

FIG. 11C is a polar plot of a simulated intensity profile of anembodiment of a pendant luminaire.

FIG. 12A is a view of an embodiment of a luminaire used to providedirect and indirect components of a light intensity distribution.

FIG. 12B is a view of another embodiment of a luminaire used to providedirect and indirect components of a light intensity distribution.

FIGS. 13A-13F show different aspects of an asymmetric luminaire.

FIGS. 14A-14G show different aspects of a troffer luminaire.

FIGS. 15A-15D show different arrangements of luminaires.

FIGS. 16A-16F show different arrangements of asymmetric luminaires.

FIGS. 17A-17C are views of an embodiment of a task luminaire.

FIG. 18 is an intensity profile of an embodiment of a task luminaire.

FIGS. 19A-19C show aspects of an intensity distribution associated witha task luminaire.

FIGS. 20A-20C show other aspects of the intensity distributionassociated with a task luminaire.

FIGS. 21A and 21B are views of another embodiment of a task luminaire.

FIG. 22 is an intensity profile associated with the other embodiment ofthe task luminaire.

FIGS. 23A-23C show aspects of an intensity distribution associated withthe other embodiment of the task luminaire.

FIG. 24A-24C show other aspects of an intensity distribution associatedwith the other embodiment of the task luminaire.

FIG. 25 is a view of a hollow embodiment of a task luminaire.

FIG. 26 is an intensity profile of the hollow embodiment of the taskluminaire.

FIG. 27A-27F show aspects of an intensity distribution associated withthe hollow embodiment of the task luminaire.

FIG. 28 is a view of a hollow embodiment of a luminaire used to providedirect and indirect components of a light intensity distribution.

FIGS. 29A-29C are views of another hollow embodiment of a luminaire usedto provide direct and indirect components of a light intensitydistribution.

FIG. 30 is an intensity profile of the other hollow embodiment of aluminaire.

FIG. 31A-31C show aspects of an intensity distribution associated withthe other hollow embodiment of the luminaire.

FIG. 32A-32C show aspects of an intensity distribution associated withthe other hollow embodiment of the luminaire.

FIG. 33A-33C show aspects of an intensity distribution associated withthe other hollow embodiment of the luminaire.

FIGS. 34A-34C are views of embodiments of LEE strips for a luminaire.

FIG. 34D is a light emission-pattern of LEE strips.

FIG. 35 is a view of another embodiment of a LEE strip.

FIG. 36A-36H show aspects of optical couplers of a luminaire.

FIG. 37 is a view of an embodiment of an LEE and optical coupler.

FIGS. 38A-38B are views of an embodiment of a luminaire with rotationalsymmetry.

FIG. 39 is a view of another embodiment of a luminaire with rotationalsymmetry.

FIG. 40 is a view of yet another embodiment of a luminaire withrotational symmetry.

FIGS. 41-42 are views of an embodiment of a luminaire system.

FIG. 43 is a view of example components for forming LEE strips for aluminaire.

FIG. 44 is a view of an embodiment of a light guide and opticalextractor for a luminaire.

FIG. 45A-45B are views of a hollow embodiment of a luminaire withrotational symmetry.

FIGS. 46A-46B and 47 show components of the hollow embodiment of aluminaire with rotational symmetry.

FIG. 48 is an intensity profile of the luminaire of the hollowembodiment of a luminaire with rotational symmetry.

FIG. 49A-49C show aspects of an intensity distribution associated withthe hollow embodiment of a luminaire with rotational symmetry.

Like elements in different figures are identified with the samereference numeral.

DETAILED DESCRIPTION

Referring to FIG. 1, in which a Cartesian coordinate system is shown forreference, a luminaire 100 for illuminating a target surface can includeat least a substrate 110, one or more LEEs 112 disposed on the substrate110, one or more optical couplers 120, an optional light guide 130, andan optical extractor 140. The LEEs 112 emit light, during operation,light in a first angular range 115 with respect to a normal to thesubstrate 110 (e.g., the direction of the z-axis). For example, adivergence of the first angular range 115 of the light emitted by theLEEs 112 can be 150-180 sr around the normal. Optical couplers 120receive light in the first angular range 115 from LEEs 112. Each opticalcoupler 120 is configured to redirect the light received in the firstangular range 115 into a light with a second angular range 125 andredirect it into a first end 131 of light guide 130. For example, adivergence of the second angular range 125 of the light provided by theoptical couplers 120 can be 90 sr around the normal (+/−45 sr). When thelight guide 130 is not part of the luminaire 100, the optical couplers120 redirect the light with the second angular range 125 into theoptical extractor 140. The light guide 130 can guide the light to adistal end 132 of the light guide 130 away from LEEs 112. The lightguide 130 provides the guided light at the distal end 132 in an angularrange 135. In some implementations, the light guide 130 can be shaped toguide the light received from the optical couplers 120 in the secondangular range 125 and to provide the guided light in substantially thesame second angular range (135˜125) at the output end of the solid lightguide 132. Optical extractor 140 receives light with angular range 135that exits end 132 of the light guide 130 or, when the light guide 130is not part of the luminaire 100, the optical extractor 140 receives thelight with angular range 125 provided by the optical couplers 120.Optical extractor 140 includes a reflective interface that reflects thelight, which exits luminaire 100 (indicated by arrows) with first andsecond output angular ranges 142, 142′. As discussed in detail below,the output angular ranges 142, 142′ at which light exits luminaire 100depend, among other things, on the properties of optical extractor 140(e.g., geometry of the optical interfaces and optical properties of thematerials forming the extractor). These properties can be tailored toprovide extraction profiles desirable for specific lightingapplications.

In some embodiments, luminaire 100 includes one or more secondaryreflectors 150, 150′ positioned to receive at least some of light outputby the optical extractor 140 in angular ranges 142, 142′. Secondaryreflectors 150, 150′ redirect light received from the optical extractor140 in angular ranges 142, 142′, and to provide the redirected lightinto desired angular ranges 152, 152′ to illuminate the target surface.

In general, the components of luminaire 100 are arranged to redirectlight emitted from LEEs 112 away from the LEEs before the light isemitted into the ambient environment. The spatial separation of theplace of generation of the light, also referred to as the physical(light) source, from the place of extraction of the light, also referredto as the virtual light source or virtual filament, can facilitatedesign of the luminaire. For example, in some embodiments, the virtuallight source/filament can be configured to provide substantiallynon-isotropic light emission with respect to planes parallel to anoptical axis of the luminaire. In contrast, a typical incandescentfilament generally emits substantially isotropically distributed amountsof light. The virtual light source as embodied in luminaire 100 may beviewed as one or more portions of space from which substantial amountsof light appear to emanate. Furthermore, separating the LEEs, with theirpredetermined optical, thermal, electrical and mechanical constraints,from the place of light extraction, may facilitate a greater degree ofdesign freedom of the optical system of the luminaire and allows for anextended optical path, which can permit a predetermined level of lightmixing before light is emitted from the luminaire. Thus, luminaire 100may be configured to provide predetermined illumination with goodaesthetics that may be useful for a wide range of lighting applications.

In general, luminaire 100 is configured to generate light of a desiredchromaticity. In many applications, luminaire 100 is configured toprovide broadband light. Broadband light can be generated usingnominally white or off-white LEEs or colored LEEs whose emissions aremixed to provide white light. Alternatively, or additionally, whitelight can be generated using an LEE configured to emit pump light (e.g.,blue, violet or ultra-violet light) in conjunction with a wavelengthconversion material. For example, in certain embodiments, LEEs 112include GaN-based pump LEDs with an overlying phosphor layer (e.g., YAG)that creates yellow, red and/or green components to produce white light.

In some embodiments, luminaire 100 may be configured to provide coloredlight (e.g., yellow, red, green, blue light). Different LEEs inluminaire 100 can be configured to emit nominally different light underoperating conditions, for example yellow, red, green, blue, white orother color light.

In general, relatively energy efficient LEEs can be used. For example,LEEs 112 can have an output efficiency of about 50 lm/W or more (e.g.,about 75 lm/W or more, about 100 lm/W, about 125 lm/W or more, about 150lm/W or more). In certain embodiments, LEEs 112 conduct current greaterthan about 350 mA (e.g., 400 mA or more, 450 mA or more, 500 mA ormore). LEEs may be surface mount devices.

The number of LEEs in a luminaire can vary. In some embodiments,luminaire 100 can include relatively few LEEs (e.g., 10 or fewer). Insome cases, luminaire 100 can include a large number of LEEs (e.g., 100or more). In many applications, however, luminaire 100 includes between4 and 100 LEEs.

Optical coupler(s) 120 are configured to receive light from one or moreof the LEEs that are suitably disposed at an entrance aperture of theoptical coupler. In embodiments that feature multiple optical couplers,they may be integrally formed. Each optical coupler can be configured toprovide a predetermined amount of light at an exit aperture of theoptical coupler. For this purpose, each optical coupler is opticallycoupled with the corresponding LEEs and the light guide. Adjacentoptical couplers may be optically isolated or optically coupled tocontrol cross talk and/or collimation of light or other functions in oneor more planes parallel to the optical axes of the optical couplers orin other directions.

The optical couplers are configured to allow coupling of a predeterminedamount of light from one or more of the LEEs into the optical couplersand a predetermined amount of that light is provided at the exitapertures of the optical couplers. Each optical coupler is configured totransform light as it interacts with the optical coupler between theentrance aperture and the exit aperture. Such transformations, alsoreferred to as conditioning, may be regarded as transformations of thephase space of light including collimation of light (e.g. causing areduction of the divergence of the coupled light) or othertransformations, and/or preservation of etendue, light flux and/or otherparameters, for example. In some embodiments, the optical couplers areconfigured to provide light with predetermined properties to controllight losses in other components of the luminaire, including one or moreof the light guide 130, extractor 140, secondary reflector 150, 150′ orother components of the luminaire. For example, the optical couplers maybe configured so that substantially all light provided thereby canpropagate through the light guide 130 to the optical extractor 140, hasless than a predetermined divergence, is injected into the light guideat suitable angles relative to the optical interfaces of the light guide130 or has other properties.

Optical couplers can include one or more optical elements includingnon-imaging dielectric TIR concentrators, such as CPC (compoundparabolic concentrators), CECs (compound elliptical concentrators), CHC(compound hyperbolic concentrators), tapered or untapered portions,light pipes, segmented concentrators, other geometry concentrators, oneor more lenses or other optical elements, for example. In someembodiments, optical couplers and LEEs are integrally formed as a singlecomponent.

A luminaire may include a number of optical couplers that are the sameas each other or different. Optical couplers may have equal or differentprofiles or cross sections in different directions. In some embodiments,optical couplers may have varying configurations depending on theirlocation within a cluster or group of optical couplers. For example,optical couplers proximate the ends of an elongate luminaire may beconfigured with properties different from those of optical couplers nearthe center of the luminaire. Like considerations may apply inembodiments in which the optical couplers are disposed in clustersproximate an optical axis. For example, optical couplers proximate theperiphery of a cluster may be configured with properties different fromthose proximate the optical axis. An optical coupler may haverotationally symmetric and/or asymmetric cross sections, for example itmay have parabolic, elliptical, circular, hyperbolic, triangular,square, rectangular, hexagonal or other regular or irregular polygonalor other cross sections.

A portion or all of the optical coupler 120 may be made of a solidtransparent body configured to propagate light internally and solely,partially or not at all, depending on whether a specular reflectivecoating is employed on the outside of the solid transparent body, relyon TIR, or may be configured to provide a through hole that is partiallyor fully reflectively coated on one or more optical surfaces. Likeconsideration may apply to the light guide 130, the optical extractors140 or other components of the luminaire, for example. Depending on theembodiment, one or more optical couplers 120 may be configured ashollow, reflectively coated non-imaging optical couplers. One or more ofthe optical couplers 120 may include a dielectric collimating opticconfigured to provide a predetermined collimation angle. The collimationangle may be determined by the length and/or shape of respectivesurfaces of the optical coupler 120, for example. An optical coupler 120may be configured to provide substantially equal collimation about anoptical axis in rotationally symmetrical configurations or may providedifferent collimation in different directions with respect to an opticalplane of the optical coupler 120 and/or other component of theluminaire, for example.

In general, light guide 130 can have a generally regular or irregularprismatic, cylindrical, cuboid or other shape and include one or morelight guide elements. Light-guide elements may be arranged in a line ora cluster that may or may not allow light to transmit betweenlight-guide elements. Light-guide elements may be arranged in parallelwith one light-guide element for each coupler. Such configurations maybe integrally formed. Multiple light-guide elements may be arranged in acluster, the light-guide elements of the cluster coupling light into oneor more extractors 140. Multiple light-guide elements may be disposedabutting one another or placed apart at predetermined distances. Thelight guide 130 and/or one or more light-guide elements may beintegrally formed, modularly configured, arranged and/or durablydisposed via a suitably configured interconnect system duringmanufacture, installation, servicing or other event.

The light guide 130 and/or one or more light-guide elements may beconfigured to have one or more substantially reflective surfacesdefining one or more mantles that extend from a first end 131 to asecond end 132 of the light guide 130 for enclosing and enabling opticalconfinement proximate an optical axis or optical plane along which thelight guide 130 can guide light with below predetermined light losses.One or more surfaces of the mantle may be substantially parallel,tapered or otherwise arranged. Such surfaces may be substantially flator curved. Generally, the light guide 130 can have elongate ornon-elongate cross section with respect to an axes or planes of theluminaire. Non-elongate light-guides may be rotationally or otherwisesymmetric about an optical axis.

The light guide 130 is configured to guide light from the one or moreoptical couplers 120 via its optical surfaces, by total internalreflection (TIR) and/or specular reflection. Mixing of the light in thelight-guide elements may be achieved in part by the shape of the opticalsurfaces. The light guide may be configured to intermix light fromdifferent LEEs 112. In some embodiments, the light guide 130 isconfigured to mix light and to provide light with a predetermineduniformity in color and/or illuminance to the optical extractor 140.

In some embodiments, the light guide 130 has a hollow configurationhaving reflective optical surfaces on its inside that transmit lightalong the length of the hollow with predetermined light-loss properties.The reflectivity of the reflective optical surfaces may originate fromor be enhanced by reflective coatings, films, layers or other reflectiveaids. The composition of and manner in which such reflective coatingsmay be disposed and/or manufactured would be readily known by a personskilled in the art.

Optical extractor 140 is disposed at an end of the light guide 132opposite the optical coupler 120 and includes one or more reflectiveinterfaces that are configured to redirect light from the light guide130 outward away from the optical axis of the light guide 130 towardsand through one or more light-exit surfaces of the optical extractor 140into the ambient. Depending on the embodiment, the directions ofpropagation of the emitted light may be parallel, antiparallel and/oroblique, that is backward and/or forward, with respect to the opticalaxis of the light guide 130. For example, different portions of lightemitted from the optical extractor 140 may propagate upwards towards aceiling or downwards towards the surface of a table, for example,depending on the configuration, orientation and/or application of theluminaire 100. The intensity distribution is determined at least in partby the configuration of the optical extractor 140 and/or theconfiguration of other components of the luminaire including the opticalcouplers 120, or other components, for example.

The optical extractor 140 may be configured to emit one or more beams oflight with predetermined intensity distributions (i.e., into specificranges of solid angles). For example, different intensity distributionsmay be provided via different light-exit surfaces, for example on eitherside of an elongate optical extractor 140. The optical extractor 140and/or one or more portions thereof from which light appears to emanateunder operating conditions may be referred to as a virtual light source.Depending on the embodiments, the virtual light source can have anelongate or non-elongate configuration. A non-elongate configuration mayhave rotational symmetry about an optical axis. The intensitydistributions or one or more portions thereof may be configured to limitglare by limiting direct downward lighting to predetermined levels, forexample.

In some embodiments, the intensity distribution of the optical extractor140, at least in part, may be determined by the configuration anddisposition of the reflective interfaces relative to the light-exitsurfaces of the optical extractor 140. The optical extractor 140 mayinclude one or more reflective interfaces having one or more flat orcurved shapes including parabolic, hyperbolic, circular, elliptical orother shapes. In certain embodiments, the optical extractor 140 includesone or more reflective coatings to redirect light and provide a desiredemission pattern. The reflective interface may have a linear, convex,concave, hyperbolic, linear segmented or other cross section shaped as aplurality of potentially disjoint, piecewise differentiable curves, inorder to achieve a predetermined emission pattern. In general, theoptical extractor 140 may provide symmetrical or asymmetrical beamdistributions with respect to an optical axis or optical plane thereof.In elongate embodiments of an optical extractor 140, the cross sectionsof reflective interfaces and/or light-exit surfaces may change along anelongate extension thereof. Such variations may be stepwise orcontinuous. For instance, the reflective interface of the opticalextractor 140 may have a first cross section shaped as a plurality ofpotentially disjoint, piecewise differentiable first curves, and asecond cross section at a different location along the elongateextension of the reflective interface, such that the second crosssection is shaped as a different plurality of potentially disjoint,piecewise differentiable second curves.

In certain embodiments, the reflective optical interfaces may have asymmetrical or asymmetrical v-shaped or other cross section. A v-shapedcross section may also be referred to as a v-groove in elongateembodiments or a conical cavity in non-elongate embodiments. As usedherein, the term “v-groove” refers to the v-shaped cross-section throughthe reflective optical interfaces, but does not require that the opticalextractor include an actual groove. For example, in some embodiments,the optical extractor includes two portions of solid material that meetat a v-shaped interface. Such an interface is also referred to as av-groove, even though the optical extractor does not include groove.Depending on the embodiment, a v-groove may have substantially equalcross section along a length of the optical extractor or it may varydepending on the position along the elongate extension. The apex formedby such v-shaped reflective interfaces may be generally directed towardsthe light guide. In addition, the sides forming the v-groove may havelinear cross-sections, or may be non-linear (e.g., curved or faceted).Moreover, the apex of the reflective optical interfaces can be a roundedvertex with a non-zero radius of curvature.

Generally, the optical extractor 140 can be integrally or modularlyformed with the light guide 130. The optical extractor may be formed ofone or more materials equal, similar or dissimilar to that of the lightguide and include one or more different materials. Depending on theembodiment, the optical extractor 140 may be configured to redirectlight via TIR, specular and/or diffuse reflection, for example, via adielectric or metallic mirror surface, refraction and/or otherwise. Theoptical extractor 140 may include one or more coatings including one ormore films of suitable dielectric, metallic, wavelength conversionmaterial or other material. Depending on the embodiment, a modularlyformed optical extractor and light guide may include or beinterconnected with suitable connectors for durable interconnection andoptional registration during manufacture, assembly, service or otherevent. Different modular optical extractors may have differentconfigurations to provide different lighting properties. To improveoptical and/or mechanical performance, a coupling between the opticalextractor 140 and the light guide 130 may be established by employingone or more suitably transparent compounds with predetermined refractiveindices. Such compounds may include at least initially fluid substancessuch as silicone or other curable or non-curable substances. Suchsubstances may provide an adhesive function.

Each of the light-exit surfaces and/or the reflective interfaces of theoptical extractor 140 may include one or more segments, each having apredetermined shape including convex, concave, planar or other shape.Shapes of the light-exit surface and/or the reflective interfaces can bedetermined to provide predetermined levels of light extraction via theoptical extractor and to limit light losses due to back reflectionand/or absorption of light within the optical extractor.

In general, secondary reflectors 150, 150′ may be configured to redirectlight via specular and/or diffuse reflection, or in other ways (e.g.,diffraction). The secondary reflector 150 can have an elongate ornon-elongate configuration. The secondary reflector 150 can beconsidered as a modular component of the luminaire 100 that can be usedto facilitate selection of a variety of intensity distributions andtherefore generation of lighting conditions, for example, duringinstallation of the luminaire 100.

In some embodiments, the secondary reflector 150 may be disposed andconfigured to substantially extend the full length, L, of the lightguide 130 and surround at least portions of the width, which is alongthe optical path, of the light guide 130. Depending on the embodiment,the secondary reflector 150 can include one or more specular ordiffusely reflecting surfaces provided by a sheet of metal, such asaluminum or other metal, or reflective plastic, paint or other coating,for example.

The secondary reflector 150 can include partially or wholly transparentportions, as a whole be partially transparent in addition to beingreflective, or include openings that are suitably shaped to enable lightto pass and achieve a predetermined lighting effect, for example.Depending on the embodiment, the secondary reflector 150 and/or openingsin the secondary reflector 150 may be configured to provide anillumination effect, support heat dissipation or achieve bothillumination and heat dissipation effects. Openings may be configured tofacilitate airflow and thereby support convective cooling of theluminaire.

The shape of the secondary reflector 150, such as the angle with respectto the target surface, its curvature, and the width of the reflector,can be adapted to generate a predetermined emission pattern for generalillumination or particular illumination applications. The secondaryreflector 150 can include multiple reflective surfaces.

The secondary reflector 150 may be angularly and/or verticallyadjustable to allow calibration and assist in achieving a desiredintensity distribution. For this purpose, a luminaire 100 may includeone or more hinge or locking mechanisms and/or interconnectors.Corresponding luminaires may provide predetermined functionality and/ormodularity to adjustably accommodate different lighting requirements ofdifferent sized rooms including hallway, closed and open plan offices,or other spaces, for example.

The secondary reflector 150 may include an areal light source, forexample a light-emitting sheet based on a plurality of discrete lightsources or organic light emitting diode material. The areal light sourcemay be arranged to emit light on one side and reflect light on anopposite side. The reflective side may be arranged to manipulate lightas described herein and the light-emitting side may be configured toprovide auxiliary illumination. Depending on the embodiment, theluminaire 100 may be configured to provide independent control of theareal light source and the LEEs 112 that are coupled with the opticalcouplers 120.

Elongate Luminaires

Referring to FIG. 2A, in which a Cartesian coordinate system is shownfor reference, an embodiment of a luminaire module 200 includes asubstrate 210 having a plurality of LEEs 212 distributed along thesubstrate 210. The LEEs 212 are disposed at an upper edge 231 of a lightguide 230. As shorthand, the positive z-direction is referred to hereinas the “forward” direction and the negative z-direction is the“backward” direction. Sections through the luminaire parallel to the x-zplane are referred to as the “cross-section” or “cross-sectional plane”of the luminaire module. Also, luminaire module 200 extends along they-direction, so this direction is referred to as the “longitudinal”direction of the luminaire module. Lastly, embodiments of luminairemodules can have a plane of symmetry parallel to the y-z plane. This isreferred to as the “symmetry plane” of the luminaire module.

Multiple LEEs 212 are disposed on the substrate 210, although only oneof the multiple LEEs 212 is shown in FIG. 2A. For example, the pluralityof LEEs 212 can include multiple white LEDs. An optical extractor 240 isdisposed at lower edge of light guide 232. The LEEs 212 are coupled withone or more optical couplers 220 (only one of which is shown in FIG.2A).

Substrate 210, light guide 230, and optical extractor 240 extend alength L along the y-direction. Generally, L can vary as desired.Typically, L is in a range from about 1 cm to about 200 cm (e.g., 20 cmor more, 30 cm or more, 40 cm or more, 50 cm or more, 60 cm or more, 70cm or more, 80 cm or more, 100 cm or more, 125 cm or more, 150 cm ormore).

The number of LEEs 212 on the substrate 210 will generally depend, interalia, on the length L, where more LEEs are used for longer luminaires.In some embodiments, the plurality of LEEs 212 can include between 10and 1,000 LEEs (e.g., about 50 LEEs, about 100 LEEs, about 200 LEEs,about 500 LEEs). Generally, the density of luminaires (e.g., number ofLEEs per unit length) will also depend on the nominal power of the LEEsand illuminance desired from the luminaire module. For example, arelatively high density of LEEs can be used in applications where highilluminance is desired or where low power LEEs are used. In someembodiments, the luminaire module 200 has an LEE density along itslength of 0.1 LEE per centimeter or more (e.g., 0.2 per centimeter ormore, 0.5 per centimeter or more, 1 per centimeter or more, 2 percentimeter or more). In embodiments, LEEs can be evenly spaced along thelength, L, of the luminaire. In some implementations, a heat-sink 205can be attached to the substrate 210 to extract heat emitted by theplurality of LEEs 212. The heat-sink 205 can be disposed on a surface ofthe substrate 210 opposing the side of the substrate 210 on which theLEEs 212 are disposed.

Optical coupler 220 includes one or more solid pieces of transparentmaterial (e.g., glass or a transparent organic plastic, such aspolycarbonate or acrylic) having surfaces 221 and 222 positioned toreflect light from the LEEs 212 towards light guide 230. In general,surfaces 221 and 222 are shaped to collect and collimate light emittedfrom the LEEs. In the x-z cross-sectional plane, surfaces 221 and 222can be straight or curved. Examples of curved surfaces include surfaceshaving a constant radius of curvature, parabolic or hyperbolic shapes.In some embodiments, surfaces 221 and 222 are coated with a highlyreflective material (e.g., a reflective metal, such as aluminum), toprovide a highly reflective optical interface. The cross-sectionalprofile of optical coupler 220 can be uniform along the length L ofluminaire module 200. Alternatively, the cross-sectional profile canvary. For example, surfaces 221 and/or 222 can be curved out of the x-zplane. Examples of such optical couplers are discussed below inconnection with FIGS. 34-36.

The surface of optical coupler 220 adjacent upper edge of light guide231 is optically coupled to edge 231. In other words, the surfaces ofthe interface are attached using a material that substantially matchesthe refractive index of the material forming the optical coupler 220 orlight guide 230 or both. For example, optical coupler 220 can be affixedto light guide 230 using an index matching fluid, grease, or adhesive.In some embodiments, optical coupler 220 is fused to light guide 230 orthey are integrally formed from a single piece of material.

Light guide 230 is formed from a piece of transparent material (e.g.,glass or a transparent organic plastic, such as polycarbonate oracrylic) that can be the same or different from the material formingoptical couplers 220. Light guide 230 extends length L in they-direction, has a thickness uniform T in the x-direction, and a uniformdepth D in the z-direction. The dimensions D and T are generallyselected based on the desired optical properties of the light guide.During operation, light coupled into the light guide from opticalcoupler 220 (depicted by rays 252) reflects off the planar surfaces ofthe light guide by TIR and mixes within the light guide. The mixing canhelp achieve illuminance and/or color uniformity at the distal portionof the light guide 232 at optical extractor 240. The depth, D, of lightguide 230 can be selected to achieve adequate uniformity at the exitaperture (i.e., at end 232) of the light guide. In some embodiments, Dis in a range from about 1 cm to about 20 cm (e.g., 2 cm or more, 4 cmor more, 6 cm or more, 8 cm or more, 10 cm or more, 12 cm or more).

In general, optical couplers 220 are designed to restrict the angularrange of light entering the light guide 230 (e.g., to within +/−40degrees) so that at least a substantial amount of the light is coupledinto spatial modes in the light guide 230 that undergoes TIR at theplanar surfaces. Light guide 230 has a uniform thickness T, which is thedistance separating two planar opposing surfaces of the light guide.Generally, T is sufficiently large so the light guide has an aperture atupper surface 231 sufficiently large to approximately match (or exceed)the aperture of optical coupler 222. In some embodiments, T is in arange from about 0.05 cm to about 2 cm (e.g., about 0.1 cm or more,about 0.2 cm or more, about 0.5 cm or more, about 0.8 cm or more, about1 cm or more, about 1.5 cm or more). Depending on the embodiment, thenarrower the light guide the better it may mix light. A narrow lightguide also provides a narrow exit aperture. As such light emitted fromthe light guide can be considered to resemble the light emitted from aone-dimensional linear light source, also referred to as an elongatevirtual filament.

As discussed previously, length L corresponds to the length of theluminaire and can vary as desired.

While optical coupler 220 and light guide 230 are formed from solidpieces of transparent material, hollow structures are also possible. Forexample, the optical coupler 220 or the light guide 230 or both may behollow with reflective inner surfaces rather than being solid. As suchmaterial cost can be reduced and absorption in the light guide avoided.A number of specular reflective materials may be suitable for thispurpose including materials such as 3M Vikuiti™ or Miro IV™ sheet fromAlanod Corporation where greater than 90% of the incident light would beefficiently guided to the optical extractor. Optical extractor 240 isalso composed of a solid piece of transparent material (e.g., glass or atransparent organic plastic, such as polycarbonate or acrylic) that canbe the same as or different from the material forming light guide 230.In the example implementation shown in FIG. 2A, the piece of dielectricmaterial includes flat surfaces 242 and 244 and curved surfaces 246 and248. The flat surfaces 242 and 244 represent first and second portionsof a redirecting surface 243, while the curved surfaces 246 and 248represent first and second output surfaces of the luminaire module 200.

Flat surfaces 242 and 244 are coated with a highly reflective material(e.g., a highly reflective metal, such as aluminum or silver) over whicha protective coating may be disposed. Thus, surfaces 242 and 244 providea highly reflective optical interface for light entering an input end ofthe optical extractor 232′ from light guide 230. In the x-zcross-sectional plane, the lines corresponding to surfaces 242 and 244have the same length and form a v-shape that meets at a vertex 241. Ingeneral, the included angle of the v-shape can vary as desired. Forexample, in some embodiments, the included angle can be relatively small(e.g., from 30° to 60°). In certain embodiments, the included angle isin a range from 60° to 120° (e.g., about 90°). The included angle canalso be relatively large (e.g., in a range from 120° to 150° or more).In the example implementation shown in FIG. 2A, the output surfaces ofthe optical extractor 246 and 248 are curved with a constant radius ofcurvature that is the same for both. Accordingly, luminaire module 200has a plane of symmetry intersecting vertex 241 parallel to the y-zplane.

The surface of optical extractor 240 adjacent to the lower edge 232 oflight guide 230 is optically coupled to edge 232. For example, opticalextractor 240 can be affixed to light guide 230 using an index matchingfluid, grease, or adhesive. In some embodiments, optical extractor 240is fused to light guide 230 or they are integrally formed from a singlepiece of material.

During operation, light exiting light guide 230 through end 232 impingeson the reflective interfaces at portions of the redirecting surface 242and 244 and is reflected outwardly towards output surfaces 246 and 248,respectively, away from the symmetry plane of the luminaire. The firstportion of the redirecting surface 242 provides light having an angulardistribution 138 towards the output surface 246, the second portion ofthe redirecting surface 244 provides light having an angulardistribution 138′ towards the output surface 246. The light exitsoptical extractor through output surfaces 246 and 248. In general, theoutput surfaces 246 and 248 have optical power, to redirect the lightexiting the optical extractor 240 in angular ranges 142 and 142′,respectively. For example, optical extractor 240 may be configured toemit light upwards (i.e., towards the plane intersecting the LEEs andparallel to the x-y plane), downwards (i.e., away from that plane) orboth upwards and downwards. In general, the direction of light exitingthe luminaire through surfaces 246 and 248 depends on the divergence ofthe light exiting light guide 230 and the orientation of surfaces 242and 244.

Surfaces 242 and 244 may be oriented so that little or none of the lightfrom light guide 230 is transmitted by optical extractor 240 in aforward direction (i.e., in certain angular ranges relative to thepositive z-direction). In embodiments where the luminaire module 200 isattached to a ceiling so that the forward direction is towards thefloor, such configurations can help avoid glare and an appearance ofnon-uniform illuminance.

In general, the intensity distribution provided by luminaire module 200reflects the symmetry of the luminaire's structure about the y-z plane.For example, referring to FIG. 3, an exemplary intensity distribution 59includes symmetric lobes 59′ and 59″ with peak intensity atapproximately 135° and 225°, respectively, corresponding to the lightprovided by the luminaire module 200. FIG. 3 shows a plot where 0°corresponds to the forward z-direction of the Cartesian coordinatesystem shown in FIG. 2A, 180° corresponds to the negative z-direction,and 90° and 270° correspond to the positive and negative x-directions,respectively. The intensity distribution output by luminaire module 200in lux is given by the radius of the plot in a particular direction. Inaddition, FIG. 3 depicts an angular range 58 that corresponds to theangular range 142′ of the light output by the luminaire module 200through the output surface 248. The light having angular range 58propagates along a prevalent direction 56 (given by the maximumintensity of the lobe 59′ of the intensity distribution 59 associatedwith the light provided by the luminaire module 200.) Also, the lightwith angular range 58 has a divergence 57 (given by the width of thelobe 59′ of the intensity distribution 59 associated with the lightprovided by the luminaire module 200.)

In the example shown in FIG. 3, luminaire module 200 provides noillumination in the range from 90° to 270°. All the illumination isdirected into a first lobe 59″ between 112.5° and 157.5° and a secondlobe 59′ between 202.5° and 247.5°.

In general, the intensity profile of luminaire module 200 will depend onthe configuration of the optical coupler 220, the light guide 230 andthe optical extractor 240. For instance, the interplay between the shapeof the optical coupler 220, the shape of the redirecting surface 243 ofthe optical extractor 240 and the shapes of the output surfaces 246, 248of the optical extractor 240 can be used to control the angular widthand prevalent direction (orientation) of the lobes in the intensityprofile 59.

In some implementations, the orientation of the lobes 56 can be adjustedbased on the included angle of the v-shaped groove 241 formed by theportions of the redirecting surface 242 and 244. For example, a firstincluded angle results in an intensity distribution 59 with lobes 59′,59″ located at relatively smaller angles compared to lobes 59′, 59″ ofthe intensity distribution 59 that results for a second included anglelarger than the first angle. In this manner, light can be extracted fromthe luminaire module 200 in a more forward direction for the smaller oftwo included angles formed by the portions of the redirecting surface242, 244.

Furthermore, while surfaces 242 and 244 are depicted as planar surfaces,other shapes are also possible. For example, these surfaces can becurved or faceted. Curved redirecting surfaces 242 and 244 can be usedto narrow or widen the beam. Depending of the divergence of the angularrange of the light that is received at the input end of the opticalextractor 232′, concave reflective surfaces 242, 244 can narrow thelobes 98′, 98″ output by the optical extractor 240 (and illustrated inFIG. 3), while convex reflective surfaces 242, 244 can widen the lobes98′, 98″ output by the optical extractor 240. As such, suitablyconfigured redirecting surfaces 242, 244 may introduce convergence ordivergence into the light. Such surfaces can have a constant radius ofcurvature, can be parabolic, hyperbolic, or have some other curvature.

FIGS. 2B and 2D show that, for a cross-sectional plane perpendicular tothe longitudinal dimension of the luminaire module 200, the redirectingsurface 243 can have an apex 241 that separates the first and secondportions of the redirecting surface 242, 244. It should be noted thatthe apex of the redirecting surface 241 can be a rounded vertex with anon-zero radius of curvature. In the example implementations shown inFIGS. 2B and 2D, the first and second portions of the redirectingsurface 242, 244 can have first and second arcuate shapes in thecross-sectional plane perpendicular to the longitudinal dimension of theluminaire module 200. For example, the first and second portions of theredirecting surface 242, 244 can be parabolic, hyperbolic, or can haveconstant curvatures different from each other. Moreover, curvatures ofthe first and second portions of the redirecting surface 242, 244 can beboth negative (e.g., convex with respect to a direction of propagationof light from the input end of the extractor 232′ to the redirectingsurface 243), can be both positive (e.g., concave with respect to thepropagation direction), or one can be positive (convex) and the otherone can be negative (concave).

FIG. 2E shows that, for a cross-sectional plane perpendicular to thelongitudinal dimension of the luminaire module 200, the redirectingsurface 243 can be shaped as an arc of a circle. In this case, the firstand second portions of the redirecting surface 242, 244 represent firstand second portions of the arc of the circle. In the exampleimplementation illustrated in FIG. 2E, a curvature of the redirectingsurface 243 is negative (e.g., convex with respect to a direction ofpropagation of light from the input end of the extractor 232′ to theredirecting surface 243).

FIG. 2C shows that, for a cross-sectional plane perpendicular to thelongitudinal dimension of the luminaire module 200, either of the firstand second portions of the redirecting surface 242, 244 can have one ormore apexes, in addition to the apex 241 that separates the redirectingsurface 242, 244. For example, the first portion of the redirectingsurface 242 can have an apex 2411 that separates the first portion ofthe redirecting surface 242 in at least two regions thereof. The regionsof the first portion of the redirecting surface 242 separated by theapex 2411 can have linear or arcuate shapes. The two regions of thefirst portion of the redirecting surface 242 can reflect the lightreceived from the input end of the extractor 232′ in two differentangular sub-ranges, different from each other. In this manner, lightprovided by the first portion of the redirecting surface 242 be outputat the output surface 246 as to intensity lobes that can be manipulateddifferently, e.g., to illuminate different targets. Such application isdescribed below in this specification in connection with FIG. 12A. Asanother example, the second portion of the redirecting surface 244 canhave an apex 2444 that separates the second portion of the redirectingsurface 244 in at least two regions thereof.

FIG. 2F shows that, in some implementations, the first and secondportions of the redirecting surface 242, 244 can be separated, at leastin part, by a slot 245. FIG. 2G shows that, in some implementations,either the first and second portions of the redirecting surface 242, 244can include one or more slots 2455′, 2455″. Each of the slots 245,2455′, 2455″ may but does not need to extend along the entirelongitudinal direction of the luminaire module 200. Such a slot canrepresent on opening in the coating reflecting layer of the redirectingsurface 243, and is configured to allow a portion of light received fromthe input end of the extractor 232′ to transmit through the slot 245 ofthe redirecting surface 243. FIG. 2F shows that, for a cross-sectionalplane perpendicular to the longitudinal dimension of the luminairemodule 200 which intersects the slot 245, first and second curvescorresponding to the first and second portions of the redirectingsurface 242, 244 are separated by a discontinuity. Moreover, FIG. 2Gshows that, for a cross-sectional plane perpendicular to thelongitudinal dimension the luminaire module 200 which intersects theslots 2455′, 2455″, first and second curves corresponding to the firstand second portions of the redirecting surface 242, 244 include one ormore discontinuities associated with the slots 2455′, 2455″.

In addition, the curves corresponding to each of the cross-sectionalplanes illustrated in FIGS. 2B-2G can have different shapes anddifferent discontinuities in other cross-sectional planes along thelongitudinal dimension of the luminaire module 200. In general,different cross-sections of a redirecting surface 243 can have differentcombinations of disjoint or joined piecewise differentiable curves.

Moreover, the shape of output surfaces of the optical extractor 246 and248 can vary too, and thus, the surfaces 246 and 248 can steer and shapethe beam of light. For example, the radius of curvature of thesesurfaces can be selected so that the surfaces introduce a desired amountof convergence into the light. Aspheric surfaces can also be used.Similar properties noted above in connection with FIGS. 2B-2G regardingcontours of the redirecting surface of the extractor 243 incross-sectional planes perpendicular to the longitudinal dimension ofthe luminaire module 200 apply to contours of the output surfaces of theextractor 246, 248 in such cross-sectional planes.

In general, the geometry of the elements can be established using avariety of methods. For example, the geometry can be establishedempirically. Alternatively, or additionally, the geometry can beestablished using optical simulation software, such as Lighttools™,Tracepro™, FRED™ or Zemax™, for example.

In general, luminaire module 200 can be designed to emit light intodifferent angular ranges from those shown in FIG. 3. In someembodiments, luminaires can emit light into lobes have a differentdivergence or angular width that those shown in FIG. 3. For example, ingeneral, the lobes can have a width of up to 90° (e.g., 80° or less, 70°or less, 60° or less, 50° or less, 40° or less, 30° or less, 20° orless). In general, the direction in which the lobes are oriented canalso differ from the directions shown in FIG. 3. The “direction” refersto the direction at which a lobe is brightest. In FIG. 3, for example,the lobes are oriented at approx. 130 and approx. 230. In general, lobescan be directed more towards the horizontal (e.g., at an angle in theranges from 90° to 135°, such as at approx. 90°, approx. 100°, approx.110°, approx. 120°, approx. 130°, and from 225° to 270°, such as atapprox. 230°, approx. 240°, approx. 250°, approx. 260°, approx. 270°).

In general, luminaires can include other features useful for tailoringthe intensity profile. For example, in some embodiments, luminaires caninclude an optically diffuse material that scatters light, therebyhomogenizing the luminaire's intensity profile. For example, surfaces242 and 244 can be roughed or a diffusely reflecting material, ratherthan a specular reflective material, can be coated on these surfaces.Accordingly, the optical interfaces at surfaces 242 and 244 candiffusely reflect light, scattering light into broader lobes that wouldbe provided by similar structures utilizing specular reflection at theseinterfaces. In some embodiments these surfaces can include structurethat facilitates light distribution. For example, surfaces 242 and 244can each have multiple planar facets at differing orientations.Accordingly, each facet will reflect light into different directions. Insome embodiments, surfaces 242 and 244 can have structure thereon (e.g.,structural features that scatter or diffract light).

In certain embodiments, a light scattering material can be disposed onsurfaces 246 and 248 of optical extractor 240. Alternatively, oradditionally, surfaces 246 and 248 need not be surfaces having aconstant radius of curvature. For example, surfaces 246 and 248 caninclude portions having differing curvature and/or can have structurethereon (e.g., structural features that scatter or diffract light).

In some embodiments, optical extractor 240 is structured so that anegligible amount of the light propagating within at least one plane(e.g., the x-z cross-sectional plane) that is reflected by surface 242or 244 experiences TIR at light-exit surface 246 or 248. Such arelationship is referred to as a Weierstrass configuration and can occurfor a spherical or cylindrical structure with a surface having radius ofcurvature R for light rays emanating from within a concentric sphericalor cylindrical region having radius R/n, where n is the refractive indexof the structure. Referring to FIG. 4, this effect is illustrated for acircular structure 300 (i.e., a cross section through a cylinder orsphere) having a surface 310 of radius R. Within structure 300 thereexists a concentric notional spherical or cylindrical surface 320 havinga radius R/n. Any light ray emanating from within notional surface 320propagating within the cross-sectional plane that is incident on surface310 of structure 300 will have an angle of incidence less than thecritical angle, so will exit structure 300 without experiencing TIR.This is illustrated in FIG. 4 by light rays 318 and 319. Light rays,such as ray 321, propagating within structure 300 in the plane but notemanating from within notional surface 320 can impinge on surface 310 atthe critical angle or greater angles of incidence. Accordingly, suchlight may be subject to TIR and won't exit structure 300. Furthermore,rays of p-polarized light that pass through a notional spacecircumscribed by an area with a radius of curvature that is smaller thanR/(1+n²)^((−1/2)), which is smaller than R/n, will not be subject toFresnel reflection at surface 310 when exiting structure 300. Thiscondition may be referred to as Brewster geometry. Embodiments may beconfigured accordingly.

Referring again to FIG. 2A, in some embodiments, all or part of surfaces242 and 244 may be located within a notional Weierstrass surface definedby surfaces 246 and 248. For example, the portions of surfaces 242 and244 that receive light exiting light guide 230 through end 232 canreside within this surface so that light within the x-z plane reflectedfrom surfaces 244 and 246 exits through surfaces 246 and 248,respectively, without experiencing TIR.

As discussed previously, light is emitted from luminaire module 200 intotwo symmetric lobes between 270° and 90° degrees (i.e., in backwarddirections). Referring to FIG. 5, in some embodiments, luminaire module200 is suspended from a ceiling 510 such that the emitted light strikesthe ceiling. For example, luminaire module 200 can be attached toceiling 510 via a cable 501 that include an electrical connectionconnecting the LEEs in luminaire module 200 to the electrical mains ofthe room in which it is installed. In some embodiments, cable 501 mayinclude multiple wires (e.g., intertwined), such as a wire sufficientstrong to support the luminaire's weight, electrical wire, and, incertain embodiments, a data connection. Due to the backwards intensityprofile, the ceiling acts to scatter and reflect the light into theambient space, as depicted by rays 512 and 514, including towards thefloor or other surface to be illuminated. Such illumination is referredto as “indirect” illumination because it does not propagate directlyfrom the luminaire to the target surface. As an indirect pendantfixture, for example, such embodiments can be configured to provide lowglare with high efficiency light coupling to the ceiling to createambient illumination.

In some implementations, a luminaire module can be a circular orelliptical torus or any other 3D sweep of a planar design, e.g., ofluminaire module 200.

In some embodiments, luminaire module 200 includes one or more secondaryreflectors to further tailor the intensity profile of the luminaire. Forexample, referring to FIG. 6, luminaire module 200 can include curvedsecondary reflectors 610 that attach to luminaire module 200 near theLEEs and extend outward into the path of the light exiting opticalextractor 240. Secondary reflectors 610 are shaped to redirect the lightfrom the optical extractor towards to the target surface, as illustratedby rays 612 and 614. In general, the surfaces of reflectors 610 can bespecular reflecting surfaces or diffusely reflecting surfaces.Furthermore, the shape of the surfaces (in this instance, concave)provides an additional degree of freedom for a designer to tailor thelight distribution profile from luminaire module 200.

In certain embodiments, secondary reflectors 610 can be partiallytransmissive. For example, reflectors 610 can include apertures thatallow some of the light from optical extractor 240 to pass through thereflectors and reflect from ceiling 510 (e.g., ray 616). Alternatively,or additionally, reflectors 610 can be formed from a reflective materialthat only partially reflects light. For example, reflectors 610 can beformed from a transparent material and a partially reflective coating(e.g., a partially silvered mirror). In this manner, luminaire module200 can provide both direct illumination (i.e., light that propagatesdirectly from the luminaire to the target surface) and indirectillumination (i.e., light that propagates via the ceiling).

The substrate 210 on which the LEEs 212 are arranged may be disposedexternal to the secondary reflectors 610 so that the secondaryreflectors do not obstruct airflow along the back surface of substrate210 on which the LEEs 212 are disposed. Secondary reflectors 610 may beconfigured to provide thermal contact with substrate 210 to aid in thedissipation of heat generated by the LEEs. Luminaire module 200 may beconfigured to provide such thermal coupling also for modularlyreplaceable secondary reflectors. Secondary reflectors 610 may form partof the heat sink for the LEEs.

While secondary reflectors 610 are depicted as having a constant radiusof curvature, in general, the shape of secondary reflectors may vary asdesired. For example, surfaces of secondary reflectors can include oneor more segments having straight, angled, segmented, curved, involute orother shape in one or two dimensions to provide a predetermined broad ornarrow emission pattern. In some embodiments, secondary reflectors haveplanar reflective surfaces. The shape of the secondary reflectors may bedetermined by tailoring algorithms to provide a desired opticalfunction, for example.

In luminaire module 200, the emission spectrum of the luminairecorresponds to the emission spectrum of the LEEs. However, in someembodiments, a wavelength-conversion material may be positioned in theluminaire, for example remote from the LEEs, so that the wavelengthspectrum of the luminaire is dependent both on the emission spectrum ofthe LEEs and the composition of the wavelength-conversion material. Ingeneral, a wavelength-conversion material can be placed in a variety ofdifferent locations in luminaire module 200. For example, awavelength-conversion material may be disposed proximate the LEEs 212,adjacent surfaces 242 and 244 of optical extractor 240, on the exitsurfaces 246 and 248 of optical extractor 240, placed at a distance fromthe exit surfaces 246 and 248 and/or at other locations. Referring toFIG. 7, in some embodiments, a layer 710 of a wavelength-conversionmaterial is disposed in the path of light exiting optical extractor 240a distance (e.g., a few millimeters to a few centimeters) from surfaces246 and 248. Such a configuration may facilitate creation of a reducedintensity source which may be reflected from secondary reflectors 610,thereby providing softer lighting. The layer 710 ofwavelength-conversion material may be attached to light guide 230, heldin place via a suitable support structure (not illustrated), disposedwithin the extractor (also not illustrated) or otherwise arranged, forexample. Wavelength-conversion material that is disposed within theextractor may be configured as a shell or other object and disposedwithin a notional area that is circumscribed by R/n or even smallerR*(1+n²)^((−1/2)), wherein R is the radius of curvature of thelight-exit surfaces (246 and 248 in FIG. 2) of the extractor and n isthe index of refraction of the portion of the extractor that is oppositeof the wavelength-conversion material as viewed from the reflectivesurfaces (242 and 244 in FIG. 2). The support structure may betransparent self-supporting structure. The light-converting materialdiffuses light as it converts the wavelengths, provides mixing of thelight and can help uniformly illuminate secondary reflectors 610.

Alternatively, or additionally, secondary reflectors 610 may contain alayer of wavelength-conversion material. This may also provide orcontribute soft, diffuse illumination. For example, the secondaryreflector includes a layer of phosphor on or below one or more suitablyreflective surfaces of the secondary reflector. Alternatively, oradditionally, the secondary reflector may include a translucent materialwith a wavelength-conversion material in close proximity that may beconfigured to allow transmission of a portion of light through thesecondary reflector to a ceiling or into the ambient behind thesecondary reflector. As such the secondary reflector may be configuredfor direct as well as mixed direct and indirect ambient illumination.

In general, luminaire module 200 can be configured in a variety of formfactors. For example, with reference to FIG. 8, in some embodiments,luminaire module 200 can be integrated into a luminaire 800 designed tobe installed in or suspended from a ceiling with ceiling panels. Forexample, luminaire 800 can have a 2′×2′ or 2′×4′ footprint (i.e., in thex-y plane), corresponding to the size of conventional modules thatsupport fluorescent luminaires. Luminaire 800 includes a carrier 810,light guide 830, an optical extractor 840, and a secondary reflector860. Luminaire 800 further includes optical couplers and a plurality ofLEEs (not illustrated) housed within carrier 810. Carrier 810 can beformed of extruded aluminum and may be attached to the secondaryreflectors 860 and the light guide 830. Secondary reflectors 860 areclosed off at two ends by walls 870 and are configured to reflect allincident light. In other words, luminaire 800 is designed for directillumination only. In FIG. 8, one of walls 870 is illustrated in cutaway to better show a portion of light guide 830 and optical extractor840. Luminaire 800 can be used alone or in multiples to form a suitablysized troffer, for example. In some embodiments, luminaire 800 includesa diffuser plate positioned, for example, to cover the opening 880 ofthe luminaire and protect the optical system from dust or otherenvironmental effects.

As explained herein, composition and geometry of components of theluminaire can affect the intensity distribution provided by theluminaire. For example, referring to FIG. 9, in some embodiments,luminaire modules can be configured to direct substantially all of thelight into a range of angles between 315° and 45° in a cross-sectionalplane of the luminaire 800, where 0° corresponds to the forwarddirection. The forward direction corresponds to a normal to thesubstrate 810 and parallel to the light guide 830, and can be toward thefloor for a luminaire mounted on a ceiling. In FIG. 9, the intensityprofile in the cross-sectional plane is given by trace 910 and theintensity profile in the symmetry plane is given by trace 920. Theintensity profile in the cross-sectional plane has maximum illuminanceat about 330° and 30°. The intensity profile in the symmetry plane alsoincludes lobes having maxima at about 330° and 30°, and also includesmaxima at about 350° and 10°. Luminaire modules may be configured todirect little or no illumination into certain angular ranges close tothe plane of the ceiling to avoid glare. For example, in the presentexample, the luminaire directs almost no illumination in ranges from 55°to 90° relative to the forward direction. This may be advantageousbecause illumination propagating from a luminaire at such directions canbe perceived as glare in certain applications (e.g., in officelighting), which is undesirable.

The simulated intensity profile in FIG. 9, and in other simulationsdescribed below, was generated using Lighttools.

Multiple direct-illumination luminaire modules can be installed in aspace to provide desired illumination for a target surface. In general,the number, density, and orientation of the modules in the space canvary as desired to provide an overall intensity profile suitable of thetarget surface. In some embodiments, arrays of similarly orientedmodules can be arranged in a ceiling. For example, referring to FIGS.10A-C, twenty five 2′×2′ modules are arranged in a 5×5 array in a40′×50′ space (8′×10′ spacing) with 9′ ceiling height to illuminate atarget surface 2.5′ off the floor. Each module has the intensitydistribution shown in FIG. 9. FIG. 10A shows a contour plot of asimulated intensity distribution on the target surface. FIG. 10B shows asimulated intensity profile through the long dimension of the targetsurface at X=0 mm. The illuminance varies between about 400 lux andabout 500 lux across this section. FIG. 10C shows a simulated intensityprofile through the short dimension of the target surfaces at Y=0 mm.The illumination drops below 450 lux within about 500 mm from the edgesof the target surface in this section, but stays within a range fromabout 450 lux to about 550 lux across the majority of the section. Theintensity profile illustrated in FIGS. 10A-10C may be suitable foroffice space, for example.

Referring to FIGS. 11A and 11B, in certain embodiments, a luminaire isconfigured as a suspended luminaire 1100, which includes a carrier 1110,a light guide 1130, an optical extractor 1140, and secondary reflectors1160. Carrier 1110 houses the LEEs and the one or more optical couplers(not shown in FIGS. 11A and 11B).

Secondary reflectors 1160 include apertures 1170. Suspended luminaire1100 is designed to provide both direct and indirect illumination.Indirect illumination results from light from optical extractor 1140that is transmitted through apertures 1170 and scatters from theceiling.

FIG. 11C shows an exemplary simulated intensity profile in thecross-sectional plane of an embodiment of suspended luminaire 1100.Here, 0° corresponds to the forward direction. Direct illuminationcorresponds to the lobes between 315° and 337.5° and between 22.5° and45°. Indirect illumination corresponds to the lobes between 90° and112.5° and between 157.5° and 180°. In this embodiment, suspendedluminaire 1100 emits negligible amounts of light into polar anglesbetween 45° and 90°, between 112.5° and 157.5°, and between 180° and315°. A suspended luminaire may be fabricated in 4 ft or 8 ft lengthsand installed in a linear arrangement for example in an officeenvironment. Such luminaires may emit about 12501 m/linear foot andprovide a peak intensity of above 1500 cd in the indirect beam componentand 800 cd in the direct beam component.

Referring to FIG. 12A, a luminaire 1200 can be configured to provideboth direct and indirect illumination on an illumination target. Anindirect portion of an intensity distribution output by the luminaire1200 can include angular ranges 1242 and 1242′. If the luminaire 1200 issuspended from a ceiling, the indirect portion of an intensitydistribution can be designed to achieve maximum illuminance uniformityon the ceiling, for example in a typical spacing arrangement ofluminaires of 8′×10′. In order to achieve good illuminance uniformity onthe ceiling at very low penetration of the luminaire 1200 into the room,the indirect portions of the intensity distribution need to exit theluminaire at oblique angles, typically with a peak intensity between 90and 110 degrees with respect to the positive z-direction and adivergence less than 20 degrees, for instance. Furthermore, it may bedesirable to minimize light emission below 90 degrees to minimize glareand to meet RP1 criteria. A direct portion of the intensity distributionoutput by the luminaire 1200 can include angular ranges 152 and 152′.The direct portion of the intensity distribution can be designed tomaximize illuminance uniformity at a desirable work surface for a givenluminaire layout of the space. The direct portion of the intensitydistribution may take the shape of a batwing distribution with peakintensity below 45 deg. The direct portion of the intensity distributionmay also be designed to minimize light emission above 55 degrees andminimize glare and to meet RP1 criteria.

The luminaire 1200 includes a substrate 210 that is elongated along ay-axis (perpendicular to the figure). A plurality of LEEs (e.g., LEDs)212 are distributed along a longitudinal dimension of the substrate 210.A normal to a surface of the substrate 210 is oriented along the z-axis.The LEEs 212 emit, during operation, light in a first angular range withrespect to the z-axis.

The luminaire 1200 includes one or more primary optics 220, a lightguide 230, a secondary optic 240, and first and second tertiary optics610, 610′. In the example illustrated in FIG. 12A, the primary optics220, the light guide 230 and the secondary optic 240 are fabricated fromtransparent materials such as glass, plastics, and the like, and have afull cross-section. Such optical components are referred to as solidoptics, e.g., solid primary optics, solid secondary optic, etc. In otherimplementations, one or more of the primary optics 220 or the lightguide 230 can be fabricated from or have coatings of reflectivematerials such as Al, Ag, certain reflective dielectrics, and the like,and have hollow cross-section. The latter optical components can bereferred to as hollow optics. Examples of such primary optics 220(optical couplers) are discussed below in connection with FIGS. 34-36.

Referring again to FIG. 12A, the one or more solid primary optics 220are arranged in an elongated configuration along the longitudinaldimension and coupled with the LEEs 212. Moreover, the one or more solidprimary optics 220 are shaped to redirect light received from the LEEs212 in the first angular range, and to provide the redirected light in asecond angular range. A divergence of the second angular range issmaller than a divergence of the first angular range at least in a planex-z perpendicular to the longitudinal dimension of the luminaire 1200.

The solid light guide 230 also is elongated in the longitudinaldimension. The solid light guide 230 is coupled to the one or more solidprimary optics 220 to receive the light provided by the solid primaryoptic 220 in the second angular range. Additionally, the solid lightguide 230 is shaped to guide the light received from the solid primaryoptic 220 in the second angular range and to provide the guided light insubstantially the same second angular range to the solid secondary optic240.

The solid secondary optic 240 also is elongated in the longitudinaldimension. Further, the solid secondary optic 240 is coupled to thesolid light guide 230 to receive the light provided by the solid lightguide 230 in the second angular range. Moreover, the solid secondaryoptic 240 extracts the received light into first and second outputangular ranges 142, 142′, as described in detail above in connectionwith FIG. 2A. In the example implementation illustrated in FIG. 12A, thesolid secondary optic 240 has a symmetric profile in a cross-sectionalplane x-y perpendicular to the longitudinal dimension of the luminaire1200, such that the first and second output angular ranges 142, 142′have the same divergence. In addition, a redirecting surface of thesolid secondary optic 240 of the luminaire 1200 was described above inconnection with FIG. 2C. A shape of the redirecting surface 243 of theluminaire 1200, e.g., a relative position of the three apexes thereof,2411, 241, 2444, and a relative orientation of facets of the redirectingsurface defined by the apexes, can separate each of the first and secondoutput angular ranges 142, 142′ into portions of extracted light thatcan be used to form indirect and direct components of an intensitydistribution associated with the luminaire 1200.

Optical surfaces and/or interfaces of the solid secondary optic 240 caninclude one or more parabolic, hyperbolic, spherical, aspherical,facetted, segmented, polygonal, or otherwise shaped portions, asdescribed above in connection with FIGS. 2A-2G, for example.

In the example implementation illustrated in FIG. 12A, light provided bythe luminaire 1200 in a first portion 1242 of the first output angularrange 142 and in a first portion 1242′ of the second output angularrange 142′ can form the indirect component of the intensity distributionassociated with the luminaire 1200. As described above in thisspecification, the indirect component of the intensity distribution canbe used to illuminate an object (e.g., a ceiling to which the luminaire1200 is attached) different from an illumination target, and as such, toindirectly illuminate the illumination target.

Additionally, light provided by the luminaire 1200 in the second portion1241 of the first output angular range 142 can be redirected by thefirst tertiary optic 610 in a first target angular range 152, and lightprovided by the luminaire 1200 in a second portion 1241′ of the secondoutput angular range 142′ can be redirected by the second tertiary optic610′ in a second target angular range 152′. In this manner, the firstand second target angular ranges 152, 152′ can form a direct componentof the intensity distribution associated with the luminaire 1200 todirectly illuminate the illumination target. Shapes of the first andsecond tertiary optics may be tailored to achieve the desiredillumination pattern. The profile of the tertiary optic may be linear,segmented linear, free form shaped, parabolic, elliptical, hyperbolicalor any other shape in order to provide the desired function. In apreferred embodiment the optical power of the tertiary optic exists onlyin the plane perpendicular to the linear direction of the luminaireenabling manufacturing by extrusion of such optical part or a standardsheet metal bending process. In a different embodiment the tertiaryoptic has optical power both in direction of the linear array andperpendicular to it.

While the foregoing embodiments of luminaires have a symmetry planeextending in the luminaire's longitudinal direction, asymmetric formfactors are also possible. For example, in some embodiments, only onetertiary optic can be used to redirect the light extracted from by asecondary optic. FIG. 12B shows an example of such an asymmetricluminaire 1250, that can be configured to provide both direct andindirect illumination on an illumination target. In the exampleillustrated in FIG. 12B, the luminaire 1250 is elongated along they-axis and includes a substrate 210, a plurality of LEEs 212, one ormore primary optics 220 (configured as an optical collector), a lightguide 230, a secondary optic 240 (configured as an optical extractor),and a tertiary optic including at least on reflector 610. Because theprimary optics 220, the light guide 230 and the secondary optic 240 arefabricated from transparent materials have a full cross-section (in thisexample), these optical components are referred to as solid optics.

The substrate 210 has first and second opposing surfaces, such that eachof the first and second surfaces are elongated and have a longitudinaldimension (along the y-axis, perpendicular to the page) and a transversedimension (along the x-axis) shorter than the longitudinal dimension.The LEEs 212 are arranged on the first surface of the substrate 210 andare distributed along the longitudinal dimension, such that the LEEs 212emit, during operation, light in a first angular range with respect to anormal to the first surface of the substrate 210 (along the z-axis). Theone or more solid primary optics 220 can be arranged in an elongatedconfiguration along the longitudinal dimension of the first surface andare coupled with the LEEs. In some implementations, the one or moreprimary optics 220 may include indexing and reference features that canbe used to accurately and repeatedly position the primary optics 220 tothe LEEs 212. The one or more solid primary optics 220 are shaped toredirect light received from the LEEs 212 in the first angular range,and to provide the redirected light in a second angular range. Adivergence of the second angular range is smaller than a divergence ofthe first angular range at least in a plane x-z perpendicular to thelongitudinal dimension of the luminaire 1250. Examples of such solidprimary optics 220 (couplers) are described in detail below inconnection with FIGS. 34-36.

The solid light guide 230 includes input and output ends 231, 232. Theinput and output ends of the solid light guide 231, 232 are elongated inthe longitudinal dimension and have substantially the same shape. Theinput end of the solid light guide 231 can be coupled to the one or moresolid primary optics 220 to receive the light provided by the solidprimary optic 220 in the second angular range. Additionally, the solidlight guide 230 is shaped to guide the light received from the solidprimary optic 220 in the second angular range and to provide the guidedlight in substantially the same second angular range with respect to thefirst surface of the substrate 210 at the output end of the solid lightguide 232.

The solid secondary optic 240 includes an input end 232′, a redirectingsurface 243 opposing the input end 232′ and first and second outputsurfaces 246, 248. Each of the input end 232′, and redirecting 243,first output 246 and second output 248 surfaces of the solid secondaryoptic 240 are elongated along the longitudinal dimension. The input endof the solid secondary optic 231′ is coupled to the output end of thesolid light guide 232 to receive the light provided by the solid lightguide 230 in the second angular range. The redirecting surface 243 hasfirst and second portions 242, 244 that reflect the light received atthe input end of the solid secondary optic 232′ in the second angularrange, and provide the reflected light in third and fourth angularranges with respect to the normal to the first surface of the substrate210 towards the first and second output surfaces 246, 248, respectively.Here, at least prevalent directions of propagation of light in the thirdand fourth angular ranges are different from each other and from aprevalent direction of propagation of light in the second angular rangeat least perpendicular to the longitudinal dimension of the firstsurface of the substrate 210. In the example implementation illustratedin FIG. 12B, the first and second portions of the redirecting surface242, 244 have arcuate shapes in the x-z cross-sectional plane, (see FIG.2C). Thus, divergences of the third and fourth angular ranges aredifferent from a divergence of the second angular range. Additionally,if a curvature of the first portion of the redirecting surface 242 isdifferent from a curvature of the second portion of the redirectingsurface 244, then the divergences of the third and fourth angular rangesalso are different from each other. In general, the first and secondportions of the redirecting surface 242, 244 can include one or moreparabolic, hyperbolic, spherical, aspherical, facetted, segmented,polygonal, or otherwise shaped portions, as described above inconnection with FIGS. 2A-2G, for example.

Referring again to FIG. 12B, the first output surface 246 is shaped torefract the light provided by the first portion of the redirectingsurface 242 in the third angular range as first refracted light, and tooutput the first refracted light in a fifth angular range 142 withrespect to the normal to the first surface of the substrate 210 outsidethe first output surface of the solid secondary optic 246. A shape ofthe first output surface 246 can be tailored such that the fifth angularrange 142 is different than or substantially the same as the thirdangular range. Additionally, the second output surface 248 is shaped torefract the light provided by the second portion of the redirectingsurface 244 in the fourth angular range as second refracted light, andto output the second refracted light in a sixth angular range 142′ withrespect to the normal of the first surface of the substrate 210 outsidethe second output surface of the solid secondary optic 248. A shape ofthe second output surface 248 can be tailored such that the sixthangular range 142′ is different than or substantially the same as thefourth angular range.

The reflector 610 is elongated along the longitudinal dimension and isarranged to, at least in part, face the first output surface of thesolid secondary optic 246. The reflector 610 is shaped to reflect atleast some of the light output by the first output surface of the solidsecondary optic 246 in the fifth angular range 142 as first reflectedlight in a seventh angular range 152 with respect to the normal to thefirst surface of the substrate 210. Here, at least a prevalent directionof propagation of light of the seventh angular range 152 is differentfrom a prevalent direction of propagation of light of the fifth angularrange 142 at least in a plane x-z perpendicular to the longitudinaldimension.

In some implementations, the reflector 610 is spaced apart from thefirst output surface of the solid secondary optic 246. For example, thereflector 610 can be thermally coupled to the substrate 210 to extractat least some of the heat generated by the LEEs during operation. Inother implementations, an edge of the reflector 610 can be coupled to anedge of the first output surface of the solid secondary optic 246, alongan edge where the solid secondary optic 240 is attached to the lightguide 230. Moreover, at least a portion of the reflector 610 can be aninvolute of (e.g., has a shape that matches the shape of) at least aportion of the first output surface of the solid secondary optic 246.

In the example implementation shown in FIG. 12B, a first portion of theintensity distribution output by the luminaire 1250 during operationincludes at least some of the first reflected light having the seventhangular range 152. Additionally, a second portion of the intensitydistribution output by the luminaire 1250 during operation includes atleast some of the light output by the second output surface of the solidsecondary optic 248 within the sixth angular range 142′.

Diffusing power can be added on the first and second output surfaces246, 248, the reflector 610 of the tertiary optic, or added in form of aseparate diffuser in order to increase illuminance uniformity at thetarget surface.

While the luminaire 1250 is an example of an asymmetric luminaireincluding (i) an optical extractor 240 with a symmetric profile in across-sectional plane x-z, and (ii) a single reflector of the tertiaryoptic, other asymmetric form factors are possible. For example, in someembodiments, the optical extractor can have an asymmetric profile incross-section, resulting in an asymmetric intensity profile incross-section. FIG. 13A shows an exemplary embodiment of such anasymmetric luminaire 1300. Here, the asymmetric luminaire 1300 iselongated along the y-axis and includes optical collector 220, lightguide 230, and an asymmetric optical extractor 1310. FIG. 13B shows atop view (in plane x-y) of the asymmetric luminaire 1300. The lightsource of the asymmetric luminaire 1300 includes a plurality of LEEs 210distributed along a substrate 2110, elongated along the y-axis.

FIG. 13C shows aspects of the optical extractor 1310 of the asymmetricluminaire 1300. The optical extractor 1310 was simulated and includestailored reflective surfaces 1322, 1324, and tailored light-exitsurfaces 1312 and 1314. For clarity reasons, a side of the asymmetricluminaire 1300 corresponding to output surface 1312 is referred to asside “B” of the asymmetric luminaire 1300, and the opposing sidecorresponding to output surface 1314 is referred to as side “A” of theasymmetric luminaire 1300. Surfaces 1322 and 1324 are coated with areflective material to provide a reflective optical interface for lightexiting the light guide 230. Surfaces 1322 and 1324 meet at vertex 1325.FIG. 13D shows a polar plot of a simulated intensity profile of theluminaire asymmetric 1300. An intensity distribution of light outputthrough light-exit surfaces 1312 and 1314 of the asymmetric luminaire1300 includes lobes 1315 and 1317.

In general, optical extractor 1310 may have varying degrees of asymmetrywith respect to a plane of symmetry of light guide 230 which extends inthe longitudinal direction of luminaire 1300 (denoted by dotted line1301 in FIG. 13C). For example, vertex 1325 may intersect or bedisplaced (laterally offset) from the symmetry plane. Surfaces 1322 and1324 can have different dimensions in cross-section and/or can be atdifferent orientations with respect to the symmetry plane. In someembodiments, the materials forming the optical interfaces at surfaces1322 and 1324 can be different. For example, in some embodiments, one ofthese surfaces can be coated with a material that specularly reflectslight, while the other surface is coated with a material that diffuselyreflects light. Alternatively, or additionally, one or both of thesurfaces 1322, 1324 can be coated with a material that partiallytransmits light, providing direct illumination from optical extractor1310 to a work surface.

Curved light-exit surfaces 1312 and 1314 can also be different. Forexample, these surfaces can have different centers of curvature,different shapes (e.g., different radii of curvature), different arclengths, and/or different surface properties (for example, one surfacecan be coated with a diffusing material, while the other istransparent).

Accordingly, as a result of the asymmetry in optical extractor 1310,asymmetric luminaire 1300 has an asymmetric intensity profile in thecross-sectional plane. For example, luminaire 1300 can be designed todirect more light to one side of the light guide than the other.Alternatively, or additionally, luminaire 1300 can be designed to directlight into different angular ranges on different sides of light guide230.

FIG. 13E shows an exemplary embodiment of a luminaire 1350 including theasymmetric luminaire 1300 and a tertiary optic including a tertiaryreflector 610. The optical extractor 1310 outputs light on side A of theasymmetric luminaire 1300 in a first output angular range 1317, andadditional light on side B of the asymmetric luminaire 1300 in a secondoutput angular range 1315. The second output angular range 1315 can beused to provide indirect illumination on a work surface, e.g., byilluminating the ceiling above the work surface. The reflector 610 ofthe tertiary optic can shape the light output by the optical extractor1310 in the first angular range 1317, and redirect the shaped light inan angular range 1240 to provide direct illumination of the worksurface. FIG. 13F shows a polar plot of the illumination distribution1390 associated with the luminaire 1350, including an intensity lobe1315 corresponding to the indirect component of the illuminationdistribution 1390, and an intensity pattern 1240 corresponding to thedirect component of the same.

The surface profile of the reflector 610 can be tailored to obtain adesired pattern 1240 corresponding to the direct component of theillumination distribution 1390 associated with the luminaire 1350. Thereflector 610 of the tertiary optic can be fabricated from areflectively coated sheet metal. The reflector 610 of the tertiary opticcan have optical power in only one plane z-x, which may allow for aconventional metal bending processes to shape the surface of thereflector 610.

In some embodiments, multiple luminaire modules (e.g., luminaire module200, asymmetric luminaires 1300, or luminaires 1350) can be arrangedinto a luminaire system that provides a desired intensity profile. Forexample, referring to FIGS. 14A-14C, an indirect direct trofferluminaire 1400 includes four luminaire modules 1410, 1411, 1412, and1413, arranged in a square formation. Each of the luminaire modules hasan asymmetric cross-sectional profile of the type shown in FIG. 13E. Anintensity distribution provided by each of the four luminaire modules1410, 1411, 1412, and 1413 corresponds to the intensity distribution1390 associated with the luminaire 1350. The luminaire modules 1410,1411, 1412, and 1413 are oriented so that the larger lobe of the opticalextractor (i.e., surface 1312 of the optical extractor 1310corresponding to side B of the luminaire 1350) faces away from thesquare, and the reflector 610 points inward of the square. Only thereflector 610 of the tertiary optic of luminaire module 1411 is labeledin FIG. 14B.

In the example implementation shown in FIGS. 14A-14C, each pair ofadjacent luminaire modules is connected by one of connector elements1420, 1421, 1422, and 1423. In this implementation, each connectorelement has a cross-sectional profile that matches (other embodimentsmay be different) the luminaire modules, and bends through 90° in thex-y plane, forming the corners of the square. In general, connectorelements 1420, 1421, 1422, and 1423 can be formed from a variety ofmaterials, such as a plastic or a metal. The connector elements can betransparent or opaque. The connector elements can also be attached tothe luminaire modules in a variety of ways. For example, the connectorelements can be bonded to the luminaire modules using an adhesive, fusedto the luminaire modules, or attached via another device, such as aclamp. In some implementations, the outer circumference of the indirectdirect troffer luminaire 1400 may be diffuse reflective and fabricatedsimilarly to the inner coversheet 1450 out of powder coated steel. Insome implementations, an optical diffuser may be added to the reflector610 of each of the luminaire modules 1410, 1411, 1412, and 1413, or asan independent component that may cover the interior region of thesquare circumscribed by the flux manifolds (modules 1420, 1421, 1422,and 1423).

The square shaped by the flux manifolds (modules 1420, 1421, 1422, and1423) inscribes the housing of the indirect direct troffer luminaire1400 that can fit into a standard T-bar ceiling grid. For example,indirect direct troffer luminaire 1400 can have a maximum dimension inthe x-y plane that allows it to be accommodated in a panel 1490 having2′×2′ footprint (i.e., in the x-y plane), corresponding to the size ofconventional troffers that support fluorescent lights. FIG. 14B, forexample, shows an example of a luminaire mounted within a square panel1490 with dimensions shown by arrows 1430 and 1432. In some embodiments,indirect direct troffer luminaire 1400 is designed to be installed in oron a ceiling with ceiling panels 1490. FIG. 14C shows that such atroffer system, which may be about 5″ deep (in the z-axis), can reachabout 1″ into the ceiling 1490. In this manner, the indirect directtroffer luminaire 1400 protrudes about 4″ into the room. In otherimplementations, the indirect direct troffer luminaire 1400 can bedirectly ceiling mounted. The direct component of the intensitydistribution associated with the indirect direct troffer luminaire 1400is formed entirely in the inside of the square. The reflector 610 of thetertiary optic may be manufactured of non-diffuse reflective materialsuch as Alanod Miro Ag 4420, and a center coversheet 1450 may befabricated from diffuse reflective material such as powder coated steelor aluminum. The reflector 610 and coversheet 1450 can create a cavityof depth of about 2″, sufficient to place drive electronics and powerconversion electronics, which control the LEEs of luminaire module 1411and of the other three modules, into the cavity.

The indirect direct troffer luminaire 1400 may be mounted with theluminaire's longitudinal axes oriented at 45° with respect to the edgesof the square panel 1490, however other mounting orientations are alsopossible. For example, the luminaire's longitudinal axes may be mountedparallel to the edges of the square panel 1490. An arrangement at 45degrees or other oblique angles of the indirect direct troffer luminaire1400 may be used to provide more uniform illumination of rectilineartarget areas. Likewise, when multiple indirect direct troffer luminaires1400 are required to illuminate a large space they may be arranged in arectilinear array with their sides arranged at 45 degrees relative tothe axes of the array. Rotating the square shape at 45 deg to theorientation of the ceiling grid, as illustrated in FIG. 14B, isadvantageous in achieving optimum uniformity on the ceiling and worksurface as the largest spacing between the square luminaire systems isin the diagonal direction.

As the solid flux manifolds (modules 1420, 1421, 1422, and 1423) onopposite sides of the indirect direct troffer luminaire 1400 arepositioned antiparallel, a symmetric intensity distribution can beobtained. The indirect direct troffer luminaire 1400 can produce max tomin uniformity ratios of better than 2:1 on the work surface and betterthan 10:1 on the ceiling. Referring to FIG. 14D, indirect direct trofferluminaire 1400 can provide symmetric direct and indirect illumination inboth of two orthogonal planes. Trace 1510 shows an exemplary simulatedintensity profile in the x-z plane of an embodiment of indirect directtroffer luminaire 1400, while trace 1520 shows the simulated intensityprofile in the y-z plane. Here, 0° corresponds to the z-direction. Inboth planes, the luminaire provides direct illumination of similar fluxcorresponding to the lobes between −45° and 45°. Furthermore, in bothplanes, the luminaire provides indirect illumination of similar flux.The indirect illumination corresponds to lobes between 90° and 112.5°and between −90° and −112.5°. Luminaire 1400 emits negligible amounts oflight into polar angles between 45° and 90°, between −45° and −90°, andbetween 112.5° and −112.5°.

Multiple direct-indirect illumination luminaires 1400 can be installedin a space to provide desired illumination for a target surface. Ingeneral, the number, density, and orientation of the luminaires in thespace can vary as desired to provide an overall intensity profilesuitable of the target surface. In some embodiments, arrays of similarlyoriented indirect direct troffer luminaires 1400 can be arranged in aceiling. For example, referring to FIGS. 14E-G, twenty five 2′×2′indirect direct troffer luminaires 1400 are arranged in a 5×5 array in a40′×50′ space (8′×10′ spacing) with 9′ ceiling height to illuminate atarget surface 2.5′ off the floor. FIG. 14E shows a contour plot of theintensity profile on the target surface. FIG. 14F shows an intensityprofile through the long dimension of the target surface at X=0 mm. Theilluminance varies between about 300 lux and about 450 lux across thissection. FIG. 14G shows an intensity profile through the short dimensionof the target surfaces at Y=0 mm. The illumination drops below 375 luxwithin about 1,000 mm from the edges of the target surface in thissection, but stays within a range from about 375 lux to about 475 luxacross the majority of the section.

While indirect direct troffer luminaire 1400 includes four luminairemodules arranged as a square, other arrangements are possible. Forexample, luminaires of types 200, 1300, or 1350 can be arranged intodifferent polygonal shapes, e.g., triangles, rectangles (see FIG. 15A),combinations of rectangles or other quadrilaterals (see FIG. 15B),hexagons (see FIG. 15C), octagons (see FIG. 15D), etc. As anotherexample, the luminaire modules can be arranged on a circular orelliptical contour, corresponding to the contour of a polygon with avery large number of sides (N→∞). Generally, the shape of the luminairemodule can be selected to fit a desired installation. For example,rectangular luminaires can be used to fit with rectangular ceilingpanels.

Non-polygonal arrangements are also possible. Generally, luminaires canbe formed by arranging multiple luminaire modules in any segmentedshape. For example, asymmetric luminaire modules 1300 or 1350 can bearranged along a path (e.g., a line), such that near-neighbor asymmetricluminaire modules have common asymmetries (A, B)-(A,B), as illustratedin FIG. 16A, or such that the near-neighbor asymmetric luminaire moduleshave alternating asymmetries (A,B)-(B,A), as illustrated in FIG. 16B. Asanother example, the asymmetric luminaire modules can be arranged alongparallel paths, such that asymmetric luminaire modules that face eachother have common symmetries (A,B):(A,B), as illustrated in FIG. 16C, orsuch that the asymmetric luminaire modules that face each other havealternating symmetries (A,B):(B,A), as illustrated in FIG. 16D. Asanother example, the asymmetric luminaire modules can be arranged inintersecting paths (e.g., lines that intersect at 90° or at otherangles), such that near-neighbor asymmetric luminaire modules of each ofthe intersecting paths have common asymmetries (A, B)-(A,B), asillustrated in FIG. 16E, or such that the near-neighbor asymmetricluminaire modules of each of the intersecting paths have alternatingasymmetries (A, B)-(B,A), as illustrated in FIG. 16F).

The foregoing embodiments described above with reference to FIGS. 13-16involve luminaire modules that direct light to both sides of the lightguide, either in a symmetric or asymmetric manner. Other configurationsare also possible. For example, in some embodiments, luminaire modulescan be configured to direct light to only one side of the light guide.For example, referring to FIGS. 17A-17C, a luminaire 1700 is designed todirect light in the positive x-direction, but not in the negativex-direction. Luminaire 1700 includes a carrier 1710 that houses six LEEs1714 mounted on a strip 1712, and a corresponding optical collector 1720mounted adjacent each LEE. Optical collectors 1720 are shaped tocollimate light from LEEs 1714 in two orthogonal planes. Luminaire 1700also includes a light guide 1730 and an optical extractor 1740. Opticalextractor 1740 includes a reflective optical interface 1742 and alight-exit surface 1744. In cross-section, both reflective opticalinterface 1742 and light-exit surface 1744 are convex (as viewed in thedirection of propagation of light) in shape. However, light-exit surface1744 has a constant radius of curvature while the radius of curvature ofinterface 1742 varies. During operation, optical collectors 1720collimate light from LEEs 1714 and direct the light to light guide 1730.The light propagates down light guide 1730 to optical extractor 1740,and reflects from optical interface 1742 about out of the luminairethrough light-exit surface 1744. FIGS. 17B and 17C also show a mountingfixture 1750 and attachment brackets 1752 which attach luminaire 1700 tofixture 1750.

Luminaire modules that direct light to only one side of the light guide(e.g., luminaire module 1700) are suitable for applications such as tasklighting, cabinet lighting, wall wash or other lighting, where they areused to illuminate a work surfaces such as a table, a desk, countertops,walls or other target surfaces. They can be configured to uniformlyilluminate an area of the work surface, while also illuminating abacksplash to the work surface. FIG. 18 shows a simulated intensitydistribution for an exemplary embodiment of luminaire module 1700. Inthis plot, 0° corresponds to the positive x-direction. Trace 1810corresponds to intensity profile in the x-z plane and trace 1820corresponds to the intensity profile in the x-y plane. In both planes,substantially all of the light is directed into angles between −45° and45°, with peak flux at approximately −22.5° and 22.5°. In the x-z plane,the intensity profile is asymmetric, the luminaire providing significantflux at larger negative angles (i.e., out to about −45°), while the fluxdrops off significantly more at corresponding positive angles.Accordingly, such a luminaire module can efficiently illuminate abacksplash without directing corresponding amounts of light off thefront of the work surface.

FIGS. 19A-19C show plots of the simulated intensity distribution from aninstallation composed of two luminaire modules on a 1200 mm×600 mm worksurface. The X-axis shows the long dimension of the work surface and theY-axis shows the short dimension. FIG. 19A shows a contour plot of theilluminance across the work surface, FIG. 19B shows a plot ofilluminance (in lux) vs. Y position (in mm) at X=0 mm, and FIG. 19Cshows a plot of illuminance (in lux) vs. X position (in mm). Illuminancevaries between about 300 lux and 600 lux in the Y-direction and betweenabout 400 lux and about 500 lux for the central 1,000 mm of the worksurface in the X-direction, falling off nearer to the edges.

FIGS. 20A-20C show plots of the simulated intensity distribution fromthe same installation as depicted in FIGS. 19A-19C on a 2,000 mm×400 mmback surface. The X-axis shows the long dimension of the back surfaceand the Y-axis shows the short dimension. FIG. 20A shows a contour plotof the illuminance across the work surface, FIG. 20B shows a plot ofilluminance (in lux) vs. Y position (in mm) at X=0 mm, and FIG. 20Cshows a plot of illuminance (in lux) vs. X position (in mm). Illuminancevaries between about 150 lux and 250 lux in the Y-direction up to thetop 100 mm of the back surface, where it falls off, and between about150 lux and about 250 lux for the central 1,000 mm of the back surfacein the X-direction, falling off nearer to the edges.

In some embodiments, certain components of the luminaires describedpreviously can be omitted from the design. For example, certainembodiments need not include a light guide to guide light from theoptical collector to the optical extractor. Where the collimation of thecollectors is sufficient, they may be sufficient to direct the light tothe optical extractor without the need to confine the light to a lightguide. Moreover, such embodiments need not include a transparent opticalelement for the optical extractor, and instead can be composed of one ormore reflective surfaces. For example, FIGS. 21A and 21B show anembodiment of a luminaire 2100 similar to luminaire 1700 that includes acurved mirror 2130 spaced apart from collectors 2120, rather than alight guide and solid optical extractor. Luminaire 2100 also includes astrip 2110 supporting six LEEs 2112 and electrical connector 2111. Eachcollector is positioned adjacent a corresponding LEE and collimateslight emitted from the LEE directing the light towards mirror 2130. Thecollectors are designed to collimate light in two orthogonal planes.Mirror 2130 has a concave surface shaped to redirect the light from thecollectors to illuminate a work surface.

FIG. 22 shows a simulated intensity distribution for an exemplaryembodiment of luminaire 2100. In this plot, 0° corresponds to thepositive x-direction. Trace 2210 corresponds to the intensity profile inthe x-z plane and trace 2220 corresponds to the intensity profile in thex-y plane. In both planes, substantially all of the illumination isdirected into angles between −45° and 45°, with peak flux atapproximately −22.5° and 22.5° in the x-y plane and at about 35° in thex-z plane. In the x-z plane, the intensity profile is asymmetric, theluminaire providing higher flux at positive angles.

FIGS. 23A-23C show plots of the simulated intensity distribution from aninstallation composed of two luminaires on a 2,000 mm×600 mm worksurface. The X-axis shows the long dimension of the work surface and theY-axis shows the short dimension. FIG. 23A shows a contour plot of theilluminance across the work surface, FIG. 23B shows a plot ofilluminance (in lux) vs. Y position (in mm) at X=0 mm, and FIG. 23Cshows a plot of illuminance (in lux) vs. X position (in mm). Illuminancevaries between about 300 lux and 600 lux in the Y-direction and betweenabout 300 lux and about 600 lux for the central 1,200 mm of the worksurface in the X-direction, falling off nearer to the edges.

FIGS. 24A-24C show plots of the simulated intensity distribution fromthe same installation as depicted in FIGS. 23A-23C on a 2,000 mm×400 mmback surface. The X-axis shows the long dimension of the back surfaceand the Y-axis shows the short dimension. FIG. 24A shows a contour plotof the illuminance across the work surface, FIG. 24B shows a plot ofilluminance (in lux) vs. Y position (in mm) at X=0 mm, and FIG. 24Cshows a plot of illuminance (in lux) vs. X position (in mm). Illuminancevaries between about 150 lux and 300 lux in the Y-direction up to thetop 100 mm of the back surface, where it falls off, and between about 50lux and about 150 lux for the central 1,200 mm of the back surface inthe X-direction, falling off nearer to the edges.

FIG. 25 shows another example of a task light luminaire 2500. Luminaire2500 includes substrate 2110, LEEs 2112, optical collector 2520 andreflector 2530. In contrast to the optical collectors in luminaire 2100,which provide collimation in two directions, optical collector 2520provides collimation only in the x-z plane.

FIG. 26 shows a simulated intensity distribution for an exemplaryembodiment of luminaire 2500. In this plot, 0° corresponds to thepositive x-direction. Trace 2610 corresponds to the intensity profile inthe x-z plane and trace 2620 corresponds to the intensity profile in thex-y plane. In both planes, substantially all of the illumination isdirected into angles between −45° and 45°, although in the x-y plane theintensity distribution is approximately lambertian, composed of a singlelobe with peak flux at 0°. In the x-z plane, the distribution has twodistinct lobes, with peak flux at approximately −22.5° and about 35°. Inthe x-z plane, the intensity profile is asymmetric, the luminaireproviding higher flux at positive angles.

FIGS. 27A-27C show plots of the simulated intensity distribution from aninstallation composed of two luminaires on a 2,000 mm×600 mm worksurface. The X-axis shows the long dimension of the work surface and theY-axis shows the short dimension. FIG. 27A shows a contour plot of theilluminance across the work surface, FIG. 27B shows a plot ofilluminance (in lux) vs. Y position (in mm) at X=0 mm, and FIG. 27Cshows a plot of illuminance (in lux) vs. X position (in mm). Illuminancevaries between about 400 lux and 600 lux in the Y-direction (exceptclose to one edge, where it falls off) and between about 300 lux andabout 500 lux for the central 1,000 mm of the work surface in theX-direction, falling off nearer to the edges.

FIGS. 27D-27F show plots of the simulated intensity distribution fromthe same installation as depicted in FIGS. 27A-27C on a 2,000 mm×400 mmback surface. The X-axis shows the long dimension of the back surfaceand the Y-axis shows the short dimension. FIG. 27D shows a contour plotof the illuminance across the work surface, FIG. 27E shows a plot ofilluminance (in lux) vs. Y position (in mm) at X=0 mm, and FIG. 27Fshows a plot of illuminance (in lux) vs. X position (in mm). Illuminancevaries between about 200 lux and 350 lux in the Y-direction up to thetop 100 mm of the back surface, where it falls off, and between about100 lux and about 250 lux for the central 1,000 mm of the back surfacein the X-direction, falling off nearer to the edges.

FIG. 28 shows another example of a luminaire 2800 that features hollowcomponents that are elongated along the y-axis. The luminaire 2800 isconfigured to provide asymmetric illumination in cross-section x-z andincludes a substrate 2110, a plurality of LEEs 2112, one or more primaryoptics 2120, a secondary optic 2830 and a tertiary optic 2840.

The substrate 2110 has first and second opposing surfaces, such thateach of the first and second surfaces are elongated and have alongitudinal dimension (along the y-axis) and a transverse dimension(along the x-axis) shorter than the longitudinal dimension. The LEEs2112 are arranged on the first surface of the substrate 2110 and aredistributed along the longitudinal dimension, such that the LEEs emit,during operation, light in a first angular range with respect to anormal to the first surface of the substrate 2110. For example, adivergence of the first angular can be between 150-180 sr.

The one or more primary optics 2120 are arranged in an elongatedconfiguration along the longitudinal dimension of the first surface andare coupled with the LEEs 2112. The one or more primary optics 2120 areshaped to redirect light received from the LEEs 2112 in the firstangular range, and to provide the redirected light in a second angularrange 125. A divergence of the second angular range 125 is smaller thanthe divergence of the first angular range at least in a plane x-zperpendicular to the longitudinal dimension of the first surface of thesubstrate 2110. In some implementations, the one or more primary optics2120 can be configured as one or more solid primary optics. Examples ofhollow and solid primary optics 2120 (couplers) are described in detailbelow in connection with FIGS. 34-36.

The secondary optic 2830 includes a redirecting surface 2833 elongatedalong the longitudinal dimension. The redirecting surface of thesecondary optic 2833 is spaced apart from and facing the one or more ofthe primary optics 2120. First and second portions of the redirectingsurface 2832, 2832′ reflect light received from the one or more primaryoptics 2120 in the second angular range 125, and provide the reflectedlight in third and fourth angular ranges 142, 142′ with respect to thenormal to the first surface of the substrate 2110, respectively. Atleast prevalent directions of the third and fourth angular ranges 142,142′ are different from each other and from a prevalent direction ofpropagation of light of the second angular range 125 at leastperpendicular to the longitudinal dimension of the first surface of thesubstrate 2110.

A tertiary optic includes a reflector 2840 elongated along thelongitudinal dimension. The reflector 2840 is spaced apart from andfacing the first portion of the redirecting surface of the secondaryoptic 2832. In addition, the reflector 2840 is shaped to reflect atleast some of the light provided by the first portion of the redirectingsurface of the secondary optic 2832 in the third angular range 142 withrespect to the normal of the first surface of the substrate 2110 asfirst reflected light in a fifth angular range 152 with respect to thenormal to the first surface of the substrate 2110. The fifth angularrange 152 is different than the third angular range 142. In someimplementations, the reflector 2840 can be thermally coupled with thesubstrate 2910 to extract heat produced by the LEEs 2112 duringoperation.

A first portion of an intensity distribution output by the luminaire2800 during operation includes at least some of the first reflectedlight 152. A second portion of the intensity distribution output by theluminaire 2800 during operation includes at least some of the lightprovided by the second portion of the redirecting surface of thesecondary optic 2832′ within the fourth angular range 142′.

Optical surfaces and/or interfaces of the secondary optic 2830 and/orthe reflector 2840 of the tertiary optics can include one or moreparabolic, hyperbolic, spherical, aspherical, facetted, segmented,polygonal, or otherwise shaped portions, as described above inconnection with FIGS. 2A-2G, for example.

While the foregoing embodiments of luminaires featuring hollow portionsare designed to provide asymmetric illumination in cross-section, otherconfigurations are also possible. For example, referring to FIGS.29A-29C, a hollow luminaire 2900 is designed to provide a symmetricintensity profile in cross-section. Luminaire 2900 is elongated alongthe y-axis and includes a housing 2902 that includes a substrate 2910with a plurality of LEEs 2912 and a collector 2920.

The LEEs emit light, during operation, in a first angular range withrespect to a normal to the substrate 2910 (along the z-axis). Collector2920 includes one or more hollow primary optics that include curvedsurfaces extending along strip 2910. The collector 2920 is shaped toredirect light received from the LEEs 2912 in the first angular range,and to provide the redirected light in a second angular range, such thata divergence of the second angular range is smaller than a divergence ofthe first angular range at least in a plane x-z perpendicular to thelongitudinal dimension of the luminaire 2900.

A secondary optic including a reflector 2930 is positioned in the pathof light emitted from the LEEs 2912 and redirected by collector 2920 inthe second angular range. The reflector 2930 of the primary opticincludes two planar reflective surfaces 2932, 2932′ arranged in av-shape. In cross-section, luminaire 2900 has a symmetry plane z-y 2901,which intersects the reflector 2930 at the vertex 2935 of the v-shapeformed by the reflective surfaces 2932, 2932′. The redirecting surfaces2932, 2932′ reflect light received from the collector 2920 in the secondangular range, and provide the reflected light in third and fourthangular ranges with respect to the z-axis, respectively. At leastprevalent directions of the third and fourth angular ranges aredifferent from each other and from a prevalent direction of propagationof light of the second angular range, at least perpendicular to thelongitudinal dimension of the luminaire 2900.

Luminaire 2900 also includes tertiary optics including reflectors 2940,2940′ positioned to receive light reflected from redirecting surfaces2932, 2932′, respectively, and redirect the light to the target surface.In cross-section, the reflectors 2940, 2940′ can be convex in shape. Thefirst reflector 2940 of the tertiary optics redirects light receivedfrom the first redirecting surface 2932 in the third angular range asfirst reflected light in a fifth angular range 3010 with respect to thez-axis, such that the fifth angular range 3010 is different than thethird angular range. In this manner, a direct component of an intensitydistribution output by the illumination device during operation includesat least some of the first reflected light 3010. The second reflector2940′ of the tertiary optics redirects light received from the secondredirecting surface 2932′ in the fourth angular range as secondreflected light in a sixth angular range 3010′ with respect to thez-axis, such that the sixth angular range 3010′ is different than thefourth angular range. In this manner, the direct component of theintensity distribution output by the illumination device duringoperation includes at least some of the second reflected light 3010′.

In general, the intensity distribution provided by luminaire 2900depends, inter alia, on the geometry of collector 2920, the geometry ofreflector 2930 of the secondary optic (e.g., shape and relativeorientation of the redirecting surfaces 2932, 2932′) and tertiaryreflectors 2940, 2940′ and a distance D between the collector 2920 andthe secondary optic 2930. These parameters can be tailored to provide anintensity distribution suitable for the luminaire's intended purpose.For example, the angular width of lobes in the intensity distribution incross-section depends on the degree of collimation provided bycollectors 2920 and the amount by which reflectors 2932, 2932′ and 2940,2940′ introduce divergence or convergence to the light. The directionsof lobes in the intensity distribution also depend on the relativeorientation of the reflective surfaces. FIG. 30 shows a simulatedintensity distribution for an exemplary embodiment of luminaire 2900. Inthis plot, 0° corresponds to the positive z-direction. Traces 3010,3010′ corresponds to the intensity profile in the x-z plane, and trace3020 corresponds to the intensity profile in the x-y plane. In the x-yplane the intensity distribution is approximately lambertian, composedof a single lobe with peak flux at 0°. In the x-z plane, thedistribution has two distinct narrow lobes 3010, 3010′, with peak fluxat approximately −67.5° and about 67.5°, corresponding to the fifth andsixth angular ranges, respectively. In the x-z plane, relatively littlelight is directed into the polar angle range from −45° to 45°, andalmost no light is directed into angles greater −70° or +70°.

In some implementations, the reflector 2930 of the secondary optic canbe attached to the other components of the luminaire via mountingelements 2950, 2950′ coupled at each end of the luminaire. Mountingelements 2950, 2950′ can secure and position the reflector 2930 of thesecondary optic and the reflectors 2940, 2940′ of the tertiary optics ata predefined distance, D, from the LEEs 2912 and the collectors 2920.The optical components of luminaire 2900 can be produced from a varietyof materials. For example, the components can be produced from a metal,such as aluminum, or from a plastic coated with a reflective material.

FIGS. 31A-31C show plots of the simulated intensity distribution from aninstallation composed of six luminaires 2900 arranged in a 2×3 grid inspacing of 30′ in x and 20′ in y direction in a 18,000 mm×18,000 mmtarget surface. The luminaires are suspended 300 mm from the ceiling,which is 3,000 mm high. Such a configuration may be useful forapplication in a garage lighting application, where driving trafficoccurs in y direction with 2 driving lanes and 4 parking rows). TheX-axis shows one dimension of the target surface and the Y-axis showsthe other. FIG. 31A shows a contour plot of the illuminance across thework surface, FIG. 31B shows a plot of illuminance (in lux) vs. Yposition (in mm) at X=0 mm, and FIG. 31C shows a plot of illuminance (inlux) vs. X position (in mm). Illuminance varies between about 25 lux andabout 75 lux in the Y-direction and between about 70 lux and about 150lux in the X-direction.

FIGS. 32A-32C show plots of the simulated intensity distribution fromthe same installation as depicted in FIGS. 31A-31C on a wall along the Ydirection of FIG. 31A. In FIG. 32A, the X-axis shows the horizontaldimension of the section and the Y-axis shows the vertical dimension.Dark regions in the intensity distribution are caused by structuralelements of the building. FIG. 32A shows a contour plot of theilluminance across the section, FIG. 32B shows a plot of illuminance (inlux) vs. Y position (in mm) at X=0 mm, and FIG. 32C shows a plot ofilluminance (in lux) vs. X position (in mm). Illuminance varies betweenabout 50 lux and 250 lux in the vertical direction from the targetsurface up to the about midway through the section, where it falls off,and between about 100 lux and about 175 lux for the central 17,000 mm ofthe section in the horizontal direction, falling off nearer to theedges.

FIGS. 33A-33C show plots of the simulated intensity distribution fromthe same installation as depicted in FIGS. 31A-31C on a wall along the Xdirection of FIG. 31A. In FIG. 33A, the X-axis shows the horizontaldimension of the section and the Y-axis shows the vertical dimension. Acertain amount of light provided on the walls can aid in facialrecognition, which may provide better comfort and security to parkinggarage users. FIG. 33A shows a contour plot of the illuminance acrossthe section, FIG. 33B shows a plot of illuminance (in lux) vs. Yposition (in mm) at X=0 mm, and FIG. 33C shows a plot of illuminance (inlux) vs. X position (in mm). Illuminance varies between about 50 lux and250 lux in the vertical direction from the target surface up to theabout midway through the section, where it falls off, and between about25 lux and about 125 lux for the central 17,000 mm of the section in thehorizontal direction, falling off nearer to the edges.

Structure of LEE Strips

Each of the embodiments described above includes a strip of LEEs. FIGS.34A, 34B and 34C illustrate in cross section examples of LEE strips 3400that include an extruded aluminum carrier 3434, having extended coolingsurfaces, which forms a support structure for the LEE strip 3400. Athermal adhesive layer 3436 is applied to the carrier 3434, and thesubstrate 3412 (having the LEE chips 3437 mounted thereon) is adhered tothe layer 3436. The phosphor layer 3438 may be disposed in form ofplates, sheets, from a slurry or otherwise, which may be flat or curved,are affixed over the top surfaces of the LEE chips 3437 by an adhesive,such as silicone 3431. A strip of the optical coupler sheet 3420 is thenaffixed over the LEE chips 3437. Assuming the optical couplers 3422 arehollow, the openings 3431, 3439 in the optical couplers are then filledwith a high index silicone 3439 or other encapsulant. The phosphor layer3438 can be formed from a variety of phosphor sheets and can havevarying characteristics along its length to achieve a desired uniformchromaticity and color-rendering index (CRI) along the strip 3432. Assuch the local characteristics of a phosphor layer 3438 proximate eachLEE chip 3437 can be matched to the characteristics of each LEE chip3437.

As discussed previously, a light conversion material can be incorporatedinto a luminaire. In some embodiments, a light conversion material, inthe form of a phosphor layer, is incorporated into the LEE strip. Forexample, in FIG. 34B, a flat (not illustrated) or curved phosphor layer3438 is separated from the LEE chip 3437 by a space 3431. The spacedapart disposition can reduce the thermal load on the phosphor layer3438. The space 3431 may be partially (not illustrated) or fully filledwith an encapsulant, for example, silicone may be disposed in the space3431 proximate the LEE chip 3437 leaving a gap (not illustrated) betweenthe silicone and the phosphor layer 3438. The gap can be filled with airor other low refractive-index medium to control back reflection of lightfrom the phosphor layer. The phosphor layer 3438 may be formed bydepositing a preformed layer or by curing one or more predisposedprecursor substances from which the phosphor layer 3438 is then cured.As such phosphor may be uniformly or non-uniformly deposited along thelength of the LEE strip 3432. Furthermore, the phosphor layer 3438 andthe previously noted encapsulant may be integrally formed. The phosphormay include Ce:YAG, TAG, nitride-based phosphors or other substances asnoted herein to achieve predetermined CCTs from 2800K-5000K, forexample.

In some embodiments, the optical couplers 3422 are dielectric compoundparabolic concentrators. Each optical coupler 3422 is disposed andconfigured to collect substantially all of the light from one or more ofthe LEEs in the LEE strip 3432 and narrows the solid angle of thepropagation directions of light as it passes there through. As suchlight exiting the exit aperture of an optical coupler diverges into asmaller solid angle than light received at an entrance aperture of theoptical coupler. The opening angle of the exit beams produced by theoptical couplers 3422 may be as narrow as +/−30 degrees or less, forexample. Sufficient collimation is desired to reduce non-absorptivelosses of light in the light guide. It is noted that these and otherconsiderations can further depend on the wavelengths of the lightprovided at the entrance aperture of the optical coupler as notedherein. Depending on the embodiment, an optical coupler may be about 2mm wide and 3 mm tall if used with a 500 μm LED die, approximately 6 mmwide and 8 mm tall if used with small LED packages, or have otherdimensions, for example.

FIG. 34B illustrates an optical coupler with an asymmetricalconfiguration that can redirect more light into one portion of spacethan in another with respect to corresponding optical axes and therebyprovide light from the optical coupler having an asymmetrical intensitypattern. Depending on the configuration of other components of theluminaire, for example the length and cross sections of the light guide,an asymmetrical intensity pattern from an optical coupler may bepartially or fully preserved, and may aid in providing a luminaire withpredetermined photometric properties that may suit predeterminedillumination applications. Asymmetric optical couplers may provide fortailoring of photometric output profiles for certain applications. It isnoted that such asymmetry may be achieved via suitable asymmetricconfiguration of other components of the luminaire including the lightpipe and/or the optical extractor, for example.

FIG. 34D shows an example asymmetric intensity profile 3440 at the exitof an optical coupler. An asymmetric beam distribution may be partiallyconserved by downstream (along the optical path) components of theoptical system. Depending on the embodiment, light guides typically tendto equilibrate asymmetric beam distributions over certain optical pathlengths but may at least partially conserve an asymmetric beamdistribution if properly configured. This may be accomplished if thelight guide is of sufficiently short length, for example. An asymmetricoptical coupler may thus be utilized to generate an asymmetric intensitypattern, which may be employed in luminaires for asymmetric lightingapplications, for example, for wall washing, track lighting or otherapplications. Furthermore, provided all other components of twoluminaires are the same, asymmetrical optical couplers may cause lightemission from the optical extractor that is broader than that fromsymmetrical optical couplers. As such asymmetric optical couplers mayprovide for tailoring of photometric output profiles for certainapplications.

The submount for the LEEs may be off-perpendicular angle from theoptical axis so that the normal axis of emission from the LEE is tiltedfrom the nominal perpendicular direction in either of, or incombination, the altitudinal or azimuthal directions. The angle may beused to control the far-field emission from the optical couplers thattranslates into the intensity profile of the light emitted from anoptical extractor.

The width of the completed LEE strip (or LEE line source), including thecarrier 3434, may be up to one centimeter or more. In this example, theexit aperture of the optical coupler 3422 substantially matches thewidth of the edge of the light guide, also referred to as the entranceaperture of the light guide. Such a configuration may be effective whenthe optical coupler and the light guide are integrally formed, or theiralignment can be accurately determined during manufacture or assembly,for example. In some embodiments, the exit aperture of the opticalcoupler 3422 is narrower than the entrance aperture of the light guide.Such a configuration may be effective when the optical coupler and thelight guide are modularly formed and their alignment needs can becontrolled via suitably accurate interconnect systems (not illustrated)to mitigate effects of misalignment.

FIG. 35 shows an exploded view of the aluminum heat sink 3434, thesubstrate 3412 having a plurality of LEEs thereon, and a plurality ofoptical couplers 3422 which may be integrally formed as an opticalcoupler sheet or row 3420.

FIGS. 36A, 36B and 36D illustrate perspective views of example opticalcouplers. FIG. 36C illustrates a sectional view of an LEE strip 3434including optical couplers 3422 of FIGS. 36A and 36B. In general,optical couplers may have other configurations, for example, an opticalcoupler may be configured as a truncated cone or pyramid. Exampletruncated pyramid optical couplers may have a square or other crosssection perpendicular to an optical axis. An optical coupler may have acircular, quadratic or other cross section at a receiving end andtransition into a rectangular, circular or other cross section at anopposite end. Depending on the embodiment, such or other variations inprofile may occur more than once along the length of an optical coupler.As illustrated in FIG. 36A, the example optical couplers 3422 have areceiving opening 3442 within which the LEE chip 3437 or LEE package canbe disposed. The receiving opening 3442 may be designed to maximizeextraction efficiency out of the LEE chip 3437 or LEE package. The voidbetween the LEE chip 3437 and the collimating optic may be filled withoptical encapsulation material such as silicone to maximize lightextraction efficiency.

FIG. 36B shows an example string 3421 of optical couplers 3422, alsoreferred to as an elongate configuration of optical couplers 3422, foruse in an LEE strip 3432. The string may be configured to providecollimation power in the direction of the LEE strip 3432 andperpendicular to it. Each of the optical couplers 3422 may have equal ordifferent collimation and/or other optical properties in suchdirections. An optical coupler may have continuous or discreterotational symmetry perpendicular to its optical axis, or it may have norotational symmetry with respect to the optical axis. For example,different collimation properties in different directions can be resultof at least portions of the optical coupler having a rectilinearnon-quadratic cross section perpendicular to the optical axis. Theoptical couplers 3422 may have interlocking mechanisms (not illustrated)configured to attach adjacent optical couplers 3422 into the string3421. Such mechanisms may be resiliently releasable, allowinterconnection into one or more rows of parallel strings (notillustrated) or otherwise configured, for example. Optical couplers 3422and/or a string thereof may be formed through injection molding asseparate optical couplers or in groups of connected optical couplers (upto the length of the luminaire). Depending on the embodiment, adjacentoptical couplers in a string of optical couplers 3422 may be opticallycoupled with, or decoupled from one another to maintain transmission oflight at the abutting interfaces between them below, at or above apredetermined level. Such configuration may depend on whether theoptical couplers have a cavity or solid bulk configuration and whetherthey rely on total internal reflection and/or mirrored surfaces. It isnoted that an optical coupler as illustrated in FIG. 36A may also beused individually in a rotationally symmetrical luminaire, for example,examples of which are discussed below.

As discussed previously, the optical couplers in an LEE string may beoptically isolated or coupled to provide predetermined collimation oflight within one or more planes parallel to the optical axes of theoptical couplers. In some embodiments, adjacent optical couplers areoptically coupled via suitable configuration of abutting interfaces,disposition of suitable material between adjacent optical couplers,integral formation or otherwise optically coupled. Optical decouplingmay be achieved via disposition with formation of suitably sized gapsbetween individual optical couplers, or disposition of suitablereflective material such as films, layers, coatings or interjectingsubstances between or on abutting interfaces of adjacent opticalcouplers. Optical couplers may be integrally formed into lines or othergroups (not illustrated) of adjacent optical couplers. Depending on theembodiment, a luminaire may include equal or different numbers ofoptical couplers within different groups of optical couplers.

FIG. 36D shows a linear optical coupler 3444 configured to collimatesubstantially only in the direction perpendicular to the length of theLEE strip 3432. The optical coupler 3444 may be formed through extrusionto predetermined lengths.

FIG. 36E shows an exemplary embodiment of an optical coupler 3620 thatincludes multiple primary optics 3421. The optical coupler 3620 can beused to achieve high collimation angles in a direction perpendicular tothe elongation of the system of FWHM 20 deg or better in the solidmaterial, while it may be advantageous to keep a design wider beam angleof over 20 deg in the opposing direction. In some implementations, aconfiguration of the primary optic 3620 can be tailored to providebatwing distribution in the direction of elongation of the system. Inorder to increase collimation in the direction perpendicular to theelongation of the system (e.g., to reduce divergence of the secondangular range), a cylindrical lens 3445 can be included as part of theprimary optics 3421 to add optical power at the entrance surface ofprimary optics 3421.

FIG. 36F shows a hollow embodiment of a primary optic 3630(corresponding e.g. to primary optics 1520 2120, 2920) configured tocollect the light emitted by the LEEs 3438 and provide collimation andbeam shaping to illuminate a secondary reflector. In this embodiment,the primary optic 3630 has optical power perpendicular to the directionof a linear LED array 3438 only and provides beam shaping only in thisdirection.

FIGS. 36G and 36H show other hollow embodiments of primary optics 3640and 3650 (each of which can be used corresponding e.g. to primary optics1520 2120, 2920) configured to have identical or different opticalpowers in the direction of the linear LEE array and perpendicular to it.In some implementations, the primary optic 3650 may have a rectangularcross section with dissimilar profile in the direction perpendicular andalong the elongation of the hollow flux manifold. In one embodimentcollimation of better than FWHM of 25 deg perpendicular to theelongation of the flux manifold may be desired while collimation inelongation of the hollow flux manifold on the order of FWHM 40 deg maybe desired.

The hollow primary optics may optically communicate with each LEEindividually (as in FIGS. 36G and 36H), or may optically communicatewith all LEDs (as in FIG. 36F) or a group of LEEs.

The profile of the hollow primary optic 3630 perpendicular to the beamdirection may be linear (as in FIG. 36F), a linear array of rotationalsymmetric profiles (as in FIG. 36G), a linear array of rectangularprofiles (as in FIG. 36H) or an array of other suitable profile.

The hollow primary optic may be reflectively coated with the coatingapplied to the side facing the source or to the side facing away fromthe source. The surface shape in direction of the emission may belinear, segmented linear, parabolic, hyperbolic, or any freeform shapesuitable to the application.

A perpendicular profile of a solid or hollow primary optic may be a twodimensional array of rectangular, triangular, rotational symmetric orother shape including individual rotational symmetric, rectangular,triangular or other profiles. The primary optic may be formedindividually, in groups of six elements, for example, or may be formedintegrally for the entire hollow flux manifold.

Rotationally Symmetric Luminaires

The foregoing embodiments of luminaires are all extended along alongitudinal luminaire direction. However, other embodiments are alsopossible. For example, many of the design principles described above canbe applied to luminaires that are rotationally symmetric about thez-axis. FIGS. 37-40 each illustrate example luminaires that display thissymmetry. Each example luminaire includes an optical coupler 3477, alight guide 3478 and an optical extractor 3480, which are integrallyformed into a solid body that can reflect light via TIR. The integralformation is achieved by injection molding. Each example luminaire alsoincludes a LEE module 3476 and a secondary reflector. The light guide3478 may also be referred to as a light pipe.

FIG. 37 illustrates a perspective view of the LEE module 3476 opticallycoupled to the optical coupler 3477 to receive light from one or moreLEEs included in the LEE module 3476. The LEE module 3476 includes oneor more LEEs (e.g., LED chips) mounted on a substrate (submount). TheLEEs are configured to emit light in a first angular range with respectto a normal to the substrate, e.g., the z-axis.

The optical coupler 3477 is configured to redirect light received fromthe one or more LEEs in the first angular range, and provide theredirected light in a second angular range at an output end of theoptical coupler 3477, such that a divergence of the second angular rangeis smaller than a divergence of the first angular range. For instance,the optical coupler 3477 can be configured to collimate light tonarrower than +/−40 degrees to satisfy TIR requirements along alongitudinal extension (along the z-axis) of the cylindrical light guide3478, as shown in FIG. 38A, or of the prismatic light guide 3478′ with Nfacets, as shown in FIG. 38B. The optical coupler 3477 has a receivingpocket (other examples can have two or more) that allows positioning ofthe LEE module 3476. The receiving pocket can be designed to providepredetermined light transfer from the LEE(s) into the optical coupler3477 for one or more LEEs. The space between the optical coupler 3477and the LEE(s) may be filled with silicone or other suitable substanceto improve optical coupling. The optical coupler 3477 may have acylindrical circumference. In other examples, it may have a polygonalshape, an elliptical shape, or other shape. The polygon has N sides,where N can be 3 for triangular shape, 4 for square shape, 5 forpentagonal shape, 6 for hexagonal shape; N can also be 7 or larger forother polygonal shapes. The exit aperture of the optical coupler 3477 isdesigned to provide good transfer of light from the optical coupler 3477into the light guides 3478, 3478′. The outside of the optical coupler3477 may be coated, which may affect whether light within the opticalcoupler is reflected by TIR or specular reflection.

In some embodiments, one or more of the LEEs may be configured to emitone or more of blue, violet or ultraviolet light which may be converted,at least in part, with one or more phosphors to generate white light,for example. Phosphors may be disposed in different locations of theluminaire, for example, in the LEE module 3476, proximate or distant ofthe LEE chips. For example, the size of the submount can be about 1 cmby 1 cm. The optical coupler 3477 has a substantially circular crosssection perpendicular to its optical axis with a receiving end allowingthe insertion of at least a portion of the LEE module 3476 into theoptical coupler 3477 in order to achieve good light extraction from theLEE module 3476.

The light guide 3478 or 3478′ is optically coupled at an input end ofthe light guide with the output end of the optical coupler 3477 and isshaped to guide light received from the optical coupler 3477 in thesecond angular range to an output end of the light guide, and to providethe guided light in substantially the same second angular range at theoutput end of the light guide. In the example illustrated in FIG. 38A, across-section 3810 perpendicular to an optical axis of the light guide3478 (e.g., the z-axis) forms a circle. In the example illustrated inFIG. 38B, a cross-section 3820 perpendicular to an optical axis of thelight guide 3478′ (e.g., the z-axis) forms a polygon with N sides, whereN>3. In some implementations, the polygon of cross-section 3820 is aregular polygon. In some implementations, the number, N, of facets ofthe prismatic light guide 3478 is selected to be larger than a thresholdnumber of facets, N>N₀. The threshold N₀ depends on (i) a transversedimension of the prismatic guide 3478′ (in a cross sectional planeperpendicular to the z-axis), and an index of refraction of the lightguide 3478′. The threshold number of facets represents a number offacets N₀ for which an angle between adjacent facets of the prismaticlight guide 3478′ is such that light propagating in a cross sectionperpendicular to the optical axis z cannot undergo TIR.

In some implementations, the number, N, of facets of the prismatic lightguide 3478′ is selected such that the prismatic light guide 3478 has noparallel facets. In some implementations, the number of facets, N, ofthe prismatic light guide 3478 is to be an odd number. In the latterimplementations, development of transverse modes in the prismatic lightguide 3478′ can be avoided. In general, the prismatic light guide 3478′can blur otherwise occurring hot spots from bright LEEs.

The optical extractor 3480 is optically coupled with the output end ofthe light guide 3478 or 3478′ at an input end of the optical extractor3480 to receive light from the light guide 3478 or 3478′. The opticalextractor 3480 has a redirecting surface spaced from the input end ofthe optical extractor 3480 and an output surface. The redirectingsurface has an apex facing the input end of the optical extractor 3480and is shaped to reflect light received at the input end of the opticalextractor 3480 in the second angular range and provide the reflectedlight in a third angular range towards the output surface. The outputsurface is shaped to refract the light provided by the redirectingsurface in the third angular range as refracted light and to output therefracted light in a fourth angular range outside the output surface ofthe optical extractor 3480. The optical extractor 3480 is substantiallyrotationally symmetric about the optical axis (e.g., the z-axis) of thelight pipe 3478 or 3478′ through the apex.

As such, the optical extractor 3480 provides a substantiallyrotationally symmetric intensity distribution. It is noted, that thismay be different in other examples. Light can be output from the opticalextractor 3480 into 360 degrees outward away from the optical extractor3480 and a portion of that light back toward a notional planeperpendicular to the optical axis through the LEE module 3476. Theintensity distribution of the light output from the optical extractor3480 generally resembles a portion of the light emission of a point-likelight source.

The light that is output by the optical extractor 3480 is furtherredirected and shaped in the example luminaires by a respectivesecondary reflector to provide predetermined intensity distributions.Optical surfaces and/or interfaces of the optical extractor 3480 and/orthe secondary reflector can include one or more parabolic, hyperbolic,spherical, aspherical, facetted, segmented, polygonal, or otherwiseshaped portions, as described above in connection with FIGS. 2A-2G, forexample.

In this example, the optical extractor 3480 is shaped in a continuousrotationally symmetrical manner and can create substantially symmetricalradiation patterns. In other examples, the optical extractor 3480 canhave a finite number of discrete regular repeating patterns or facets,which can be used, for example, to create an appearance associated withfacetted glass or other transparent material or to blur otherwiseoccurring hot spots from bright light sources. The reflective interfaceof the optical extractor 3480 may additionally be coated with a suitablythick layer of silver or other metal such that no light can escape therethrough. Such a coating may change the nature of the reflection of lightinside the optical extractor 3480 from TIR to specular reflection.

FIG. 39 is a perspective view of the light guide 3478 and a reflector3482 for redirecting and shaping the light output by the opticalextractor 3480 toward the surface to be illuminated. The reflector optichas rotational symmetry about the optical axis (e.g., the z-axis) and isshaped to reflect at least some of the light output by the outputsurface of the optical extractor 3480 in the fourth angular range asreflected light, and to provide the reflected light in a fifth angularrange, such that the fifth angular range is different than the fourthangular range. The reflector 3482 may have any shape for creating thedesired intensity distribution from light it receives from the opticalextractor 3480, e.g., parabolic. In some implementations, the reflector3482 may have an irregular surface, have peened indentations, facets,grooves, or other optically active structures that could provideadditional control over beam shaping, color mixing and/orhomogenization, for example as may be desired for functional ordecorative purposes.

The reflector 3482 can include a reflective metal, such as aluminum orsilver, or a material coated with a reflective film, for exampleAlanod's Miro™ or 3M's Vikuiti™. The luminaire of FIG. 34 may findapplication as a replacement luminaire for MR16, GU10, PAR20, PAR30, PAR38, AR111, or similar luminaires, or may be configured and assembled ina light fixture creating a pendant light, a down light, a track light ora desk luminaire. The reflector 3482 may be configured to allow somelight to escape via holes (not illustrated) provided in the reflector3482, for example to illuminate a ceiling.

In one embodiment, the reflector 3482 reflects substantially all lightemitted from the optical extractor 3480. The shape of the reflector 3482may be designed to uniformly illuminate a target surface. The reflector3482 may also be adjustable relative to the optical extractor 3480. Forexample, the luminaire may be configured to permit such adjustment inthe field or during manufacturing to modify the beam characteristics ofthe luminaire. The reflector 3482 may also exhibit non-rotationalsymmetry with the ability to be field rotatable to steer the beamdistribution in the illumination region.

FIG. 40 illustrates a perspective view of an example luminaire similarto the one of FIG. 39. The luminaire includes a light guide (3478 or3478′) and a reflector 3488 for reflecting the light toward a targetsurface. This example luminaire utilizes a reflector 3488 with afacetted reflective surface 3490. The facetted reflective surface 3490includes a plurality of substantially planar segments. Furthermore, thereflector 3488 can include a cylindrical side sleeve 3489.

In some embodiments, one or more light-exit surfaces are opticallycoupled with one or more reflective interfaces in a sphericalWeierstrass configuration. For example, the optical extractor 3480 isformed of a material with refractive index n and includes at least onelight-exit surface that is configured as a portion of a sphere of radiusR that is disposed so that at least a first portion of an opticallycoupled reflective interface lies within a portion of space defined by anotional sphere of radius R/n that is concentric with the sphere ofradius R that defines the light-exit surface and reflects light from thelight guide thereto. In such a case, light coming from the light guide(3478 or 3478′) that is reflected by a first portion of the reflectiveinterface into a solid angle defined by a light-exit surface relative toa corresponding reflective interface can exit through the light-exitsurface without undergoing total internal reflection.

Additional examples of luminaires configured to provide a rotationallysymmetric intensity profile are described below in this specification inconnection with FIGS. 45A-49C.

Upright Luminaires

Luminaires can be used in an upright configuration. In other words,luminaires can be used in application where the LEE is positionedunderneath, as opposed to above, the optical extractor. For example,FIG. 41 shows a cross-section of an exemplary luminaire 4100 configuredfor use as a desk lamp or pedestal lamp. The luminaire 4100 includes alight guide 4120, an optical extractor 4126, a carrier 4134, one or moreoptical couplers 4137, and one or more LEE modules 4135 on one or moresubmounts 4138. The luminaire 4100 further includes a base 4130. Examplelight rays 4122 from the LEE modules 4135 are shown propagating in thelight guide 4120. The submounts 4138 and the carrier 4134 are thermallycoupled and may be configured as a heat sink in combination with thebase 4130. The LEEs 4132 of the LEE module 4135 (see FIG. 42) may beinterconnected in series and/or parallel as determined for operativeconnection with suitable circuitry for driving the LEEs 4132.

The optical extractor 4126 reflects the light downward and outward by aspecular reflective coating as indicated by arrows. The luminaire 4100may optionally include a secondary reflector (not illustrated) disposedand suitably configured to at least partially surround the opticalextractor 4126. In this example, such a secondary reflector may bedisposed to surround the optical extractor 4126 from above so that lightthat is emitted upward from the optical extractor 4126 can be redirecteddownward towards a target surface. The base 4130 can include a switch,dimmer, heat sink or other components. The base 4130 may be configuredto provide predetermined thermal coupling to the environment and may beused as a heat sink, for example.

Luminaire 4100 can have an elongate or rotationally symmetricalconfiguration with respect to a plane perpendicular to the opticalaxis/axes of the light guide, which is an elongation perpendicular tothe plane of the illustration of FIG. 41 or a rotational symmetry aboutan optical axis in the plane of illustration. Accordingly, for example,the carrier 4134, the optical coupler 4137 and/or the submount 4138 maybe elongate and include a plurality of LEE modules 4135 along theirlength, or be substantially quadratic, circular or otherwise point-likeand include one or a cluster of LEE modules 4135. As such, the exampleluminaire 4100 can include a plurality (not illustrated) of LEE modules4135 arranged in an elongate or clustered configuration, for example.FIG. 42 shows a top view of an example LEE module 4135 including anexample configuration of LEEs 4132. The one or more LEE modules 4135 areoperatively disposed on the one or more submounts 4138.

Manufacturing

In general, the luminaires described herein may be manufactured using avariety of techniques. Manufacturing of luminaires, including thedisposition of LEE dies or packages, may be facilitated by employingcircuit board assembly techniques and placement machinery processes incombination with one or more processes as described herein. LEE dies orpackages may be disposed relative to the optical couplers withpredetermined accuracy, for example during manufacture, assembly,installation in the field or other event. Differential coefficients ofthermal expansion between different materials may be considered duringsuch deposition, for example, if components are manufactured orassembled at different temperatures.

For example, FIG. 43 shows of how LEE strips may be formed. Three layers4312, 4320 and 4328 are combined into sheets with suitablyinterconnected LEEs that can then be separated, also referred to assingulation, into LEE strips. A substrate 4312 including a printedcircuit board (PCB) panel, or other suitable support layer may beconfigured to provide predetermined electrical, mechanical and thermalproperties and interconnect functionalities. The substrate includespairs of metal pads 4314 for each LEE chip and a suitable conductiveinterconnect systems for interconnecting the LEEs of a strip in acombination of series and parallel circuitry to be driven by a powersupply. The power supply for each LEE strip or combination of LEE stripsmay be mounted on the substrate 4312 or may be a separate moduleconnected to the strip or strips by a suitable connector. Depending onthe embodiment, the substrate 4312 may include a metal core, epoxy orother PCB that can provide predetermined vertical and horizontal heatdissipation characteristics. Segmentation lines 4316 are shown where thesubstrate 4312 will be singulated to form the strips.

Optical couplers can be disposed in an optical coupler sheet 4320, whichcan be a molded sheet, such as plastic, forming an array of opticalcouplers 4322. The sheet 4320 may be coated with a reflective film.Segmentation lines 4324 are shown. Each LEE is positioned in an opticalcoupler 4322 to ensure light is effectively injected into a light guide.The optical couplers 4322 may include one or more optical elementsincluding non-imaging dielectric TIR concentrators, such as CPC(compound parabolic concentrators), CECs (compound ellipticalconcentrators), CHC (compound hyperbolic concentrators), tapered, oruntapered, light pipes, segmented concentrators, other geometryconcentrators, one or more lenses or other optical elements, forexample. Depending on the embodiment, the optical couplers 4322 may benominally equal or have different configurations. For example, opticalcouplers may have different profiles in the direction of the luminaireand/or perpendicular to the luminaire. For example, the optical couplers4322 may be rotationally symmetric, or have elliptical triangular,square, hexagonal, or multi-segment cross-sections perpendicular to thebeam direction.

The optical couplers 4322 may be integrally formed or configured fromsolid transparent material and solely rely on TIR or may be partially orfully reflectively coated on one or more surfaces. Optical couplers alsomay be hollow, or reflectively coated and/or non-imaging. Hollowreflectors can have the benefit of a shortened length over a dielectriccollimating optic for the same collimation angle.

If corresponding LEEs are employed in the luminaire, a phosphor sheet4328 may be used to convert blue or ultraviolet pump light and producewhite light in combination with the unconverted pump light, if any. Thecharacteristics of the phosphor sheet 4328 may be varied depending onthe peak wavelength of the LEEs, the desired correlated colortemperature (CCT) or spectral power distribution of the light, and otherfactors. Segmentation lines 4330 are shown. The phosphor sheet 4328 issegmented into strips or plates that are disposed in proximity to thetop surfaces of the LEE chips. The phosphor sheet 3428 also may includethree-dimensional structures (e.g., hemispherical plates) and positionedin proximity to the LEE chips within the optical couplers 4322 to reducehigh temperature effects on the phosphor.

The electrodes of bare LEE chips, or the electrodes of submounts onwhich the bare LEE chips are mounted, are operatively disposed to thePCB pads 4314. Operative disposition may be performed by ultrasonicbonding, gluing, gluing with conductive adhesive, soldering, wirebonding, ball bumping and/or other operative interconnection. The LEEsmay be flip chips, vertical chips (using a wire bond for the top LEEelectrode), horizontal non-flip with wirebonding to anode and cathode,or other type of chip.

The substrate 4312, optical coupler sheet 4320, and phosphor sheet 4328may be separated by sawing, routing, perforating, snapping, etching orotherwise, for example. The separation may be facilitated viapredetermined breaking lines, also referred to as singulation lines, forexample. The resulting strips/plates may be combined with a suitablecarrier to form an LEE strip as shown in FIGS. 34A-34C, for example.

In some embodiments, optical couplers may be manufactured, for exampleinjection molded, in groups of two or more elements and be provided withintegral registration elements or receptacles for matingly receivingexternal registration elements to assure accurate placement of opticalcouplers relative to suitably disposed LEEs. Registration elements maybe configured as indexing pins for insertion into respective holesinside a PCB board or LEE package, for example. Index matching materialsuch as silicone with suitable optical properties may be disposed toprovide a predetermined optical coupling between LEEs and the opticalcouplers. LEE packages may be operatively connected at different stagesof the noted process to the optical couplers. Depending on theembodiment, LEE packages may be electrically and/or mechanicallydisposed on a PCB before or after operative interconnection with theoptical couplers.

Optical couplers may be configured to provide one or more receivingapertures, which may be configured to provide tapered inner walls,protrusions, ribs or other elements that provide a predeterminedrestorative force to the LEEs during the mating procedure so that LEEsand optical couplers can be aligned with predetermined accuracy.

LEEs may be placed within recesses provided by optical couplers byautomated equipment and centered by tapered walls or ribs to centeredpositions with a surrounding layer of gel to index match and optionallybe cured to set their positions. An optional processing step may thenplanarize the assembly and remove excess material in preparation fortesting and subsequent electrical and mechanical bonding to a substrate.

In certain embodiments, LEEs may be molded within the optical couplersto form assemblies which then can be optionally tested as a unit andsorted according to certain properties and then can be aligned to aregistration point on the substrate prior to electrical and thermalbonding. A tab or pin on the optical coupler body may be employed thatis aligned to the substrate matching detail which also aligns theelectrical contact points of the LEEs in the x, y and z axes forelectrical and thermal bonding.

LEEs may be affixed, molded or otherwise operatively coupled with theoptical couplers. Furthermore, LEEs may be held in place by matingstructures in one or more directions by a registration detail in theinput side of the light guide. This may be performed prior to the curingof an optical interface material, which may be used to reduce Fresnellosses at the generated interface. Such steps may help constrainalignment of the electrical contact points at the bottom of the LEE dieor packages to align to a substrate for electrical and thermal bonding.

In some embodiments, the LEEs are mounted on a substrate via an adhesivethermal matching gel with a viscous solder paste between their contactsand the substrate such that they can be adjusted minute distances asthey are centered within their respective mating recesses within theoptical couplers.

Components of luminaires can be made modularly and designed to beassembled in interchangeable ways. For example, FIG. 44 shows how anoptical extractor 3870 may be modularly configured separately from alight guide 3872. The light guide 3872 includes an input end 231 (inthis example the top edge of the rectangular light guide 3872) and anoutput end 232 (in this example the bottom edge of the rectangular lightguide 3872). The optical extractor 3870 includes an input end 232′. Theinput end 232′ of the optical extractor 3870 may be affixed to theoutput end (bottom edge) 232 of the rectangular light guide 3872employing a suitably optically transparent coupling material having amatched index of refraction such as silicone. The optical extractor 3870may be held in place by the coupling material, mechanical interference,a friction fit or otherwise, for example. This configuration may beemployed to permit choosing from a selection of differently configuredoptical extractors that provide different intensity distributions bettersuited for a particular lighting application. The optical extractor 3870may also be provided with a variety of distribution optics so that theycan be joined to a common light guide 3872 in a completely modularfashion to suit the mounting height and lighting requirements of thespace.

Multiple components of a luminaire can be integrally formed. In otherwords, two or more optical components of a luminaire can be formed fromas single piece of optical material. Integrally formed components canlimit Fresnel losses that occur at optical interfaces where refractiveindices of adjacent optical materials are mismatched. Integral formationcan facilitate registration and alignment of respective components of aluminaire.

Additional Embodiments

Optical components of luminaire may be configured to sustain exposure topredetermined amounts of short wavelength light, for example blue,violet or ultraviolet light. Depending on the embodiment, such light maypropagate through substantial portions of a luminaire. Exposure ofrespective components may depend on the particular locations ofphosphors. Respective components may be formed of suitably resistantmaterials. Likewise, components that assume high temperatures duringoperation of the luminaire be configured to provide predetermined heatresistance and resilience against mechanical stresses caused by thermalgradients and/or differential thermal expansion between differentcomponents. Wavelength-conversion materials and LEEs can assume highoperating temperatures.

Wavelength-conversion materials may be disposed in different amounts,concentrations and/or net conversion capabilities at differentlocations. Depending on the embodiment, the luminaire may be configuredto emit light of uniform or non-uniform chromaticity or CCT (correlatedcolor temperature) and/or emit light that is uniform or non-uniformwithin predetermined solid-angles. Luminaires with respective intensitydistributions may be configured for decorative and/or generalillumination. As such, wavelength-conversion materials may be arrangedalso to provide predetermined appearances and intensity distributions,for example. Depending on the embodiment, the luminaire may beconfigured so that light from different LEEs may be optically coupledwith different wavelength-conversion materials. The LEEs may beoperatively configured to allow independent control of different LEEsand as such allow control of how much light may be converted bydifferent wavelength-conversion materials. Depending on the embodiment,the light generated by the different wavelength-conversion materials inresponse to illumination by the different LEEs may be completely,partially or substantially not mixed, for example. Depending on thedegree of mixing, the luminaire may be configured to providecontrollable intensity distributions or control over the chromaticityand/or CCT of the emitted light.

In general, the LEEs are arranged on one or more substrates. Eachsubstrate may have a non-elongate, elongate or other shape. One or moresubstrates may be disposed on a carrier, for example a strip, disk, tileor otherwise shaped carrier configured to provide mechanical,electrical, thermal and/or optical coupling to respective elementsincluding the ambient, the light guide, optional secondary reflector orother component of the luminaire. The carrier may be configured toprovide predetermined mechanical strength, interconnectivity, heatsinking, electrical connection or other functions. Depending on theembodiment, the carrier may be configured to dissipate heat away fromLEEs directly or indirectly into the ambient. The secondary reflectormay be designed to be in thermal contact with the carrier and provide alarge surface area enabling thermal dissipation of the waste heatgenerated in the LEEs.

Generally, luminaires are configured for suspension from and/or recessin a ceiling, wall or other surface of an object, room, or other space.In such a case, the light guide may be disposed substantiallyvertically, horizontally or other direction with light inside the lightguide substantially propagating downwards, sideways or other respectivedirection. Corresponding luminaires may be rotationally symmetricalabout an optical axis or elongate. Elongate luminaire may be configuredin predetermined lengths of about two, four or six feet long, forexample. Corresponding luminaire may be configured as replacements tofluorescent tubes, recessed or suspended troffers, or provided in otherconfigurations, for example. According to some embodiments, theluminaire is configured as a rotationally symmetric luminaire such as alamp or light bulb, or other non-elongate luminaire. According to someembodiments, the luminaire is configured as a toroidal tube, which maybe considered both elongate and rotationally symmetrical.

To provide an example luminaire with approximately 5000 lm light outputto replace a 2×4 foot fluorescent fixture, about 50 1 W LEE chips, whichmay be packaged, chip-on-board, or otherwise configured high-illuminanceLEE chips need to be operatively disposed substantially equidistantlyalong a four foot LEE strip. In this case the average distance betweenthe LEE chips, also referred to as pitch, amounts to about 24 mm.Accordingly, a luminaire configured to replace a typical fluorescent 2foot by 2 foot troffer needs to generate about 3000 lumens, with acommensurate type or number of LEE chips. For example, LED dies of about12-14 mil can be used for task or troffer luminaires, and LED dies ofabout 40-60 mil can be used for garage and suspended luminaires. Asanother example, the number of LEE chips required depends on theluminous flux requirement of the system, the system's opticalefficiency, and the performance of the employed LEE. If more lightoutput from the luminaire is required, the LEE chips may be disposedmore densely in two or more parallel rows of LEE strips or otherwisegrouped.

Depending on the embodiment, such groupings of LEEs may determinealtered geometries and dimensions of the optical coupler, light guide,optical extractor and/or other components of a luminaire. It isimportant to mix the light from the LEE chips to obtain good illuminanceand color uniformity along the length of the light fixture.

According to another example, a luminaire of approximately 1200 mmlength is configured with approximately 100 medium flux LEEs (such asNichia NS2L-157 devices) to provide approximately 5000 lumens (lm) ofluminous flux. Those devices can be placed on a single PCB strip at aspacing of about 12 mm. Such or other luminaires described herein may beconfigured for suspension from a ceiling.

According to another example, a luminaire is configured as a replacementfor a 2 foot or 4 foot long fluorescent tube. The luminaire can have asuitable length for placement in the housing of a two feet by two feetor two feet by four feet troffer. In order to provide the flux of a 4feet long fluorescent lamp of about 3000 lm, approximately 30 LEEs, forexample 1 mm by 1 mm LEEs of 100 lm each, may be used spaced apart atapproximately 40 mm per luminaire.

A luminaire according to an embodiment may be configured to replace a2-foot by 2-foot troffer. In such a luminaire the LEEs may be disposedin two rows each having a length of about 600 mm. Each row can then becoupled with an elongate system as described herein. To be able toprovide for example 1500 lm output from each row, a certain number ofLEEs per row is required with each row having LEEs spaced at apredetermined distance, for example. Nominally, for example, 30 LEEswith a light output of 50 lm each spaced at 20 mm per row may provide1500 lm light input into the optical system of each row. Consideringinefficiencies due to optical, electrical, ageing and other effects, forexample, about 30% to about 100% more light input per row may berequired to account for such inefficiencies and achieve and maintain alight output of about 1500 lm per row. Consequently, a correspondingexample luminaire may be configured with 60 LEEs, each providing 50 lm,spaced at 10 mm per row.

It is noted that the specific number of LEEs used in such a luminairemay depend on ageing properties of the LEEs and the degree to which anLEE drive system can compensate for such properties. Ageing propertiesof LEEs can include decrease and/or increase of LEE efficacy, lightoutput, efficacy, and probability of failure and/or other propertiesthat can vary with time of operation of an LEE. Such luminaires need tobe used in combination with compatible LEE electrical drive systems inorder to be able to maintain the overall flux provided by the luminairewithin desired tolerances.

The example luminaire may be configured as a desk, pedestal or otherluminaire, for example. The example luminaire also may be configured asa replacement for a fluorescent tube, or more specifically a modularcombination of a fluorescent tube and a pair of respective T5, T8 orother fluorescent tube receiver sockets. In such an example luminairethe base can form a replacement for a pair of tube receiver sockets asusually used to releasably connect a fluorescent tube via insertingcontacts of the fluorescent tube and turning the fluorescent tube untilit locks the contacts via a suitable electromechanical mechanism toestablish an operative connection between the fluorescent tube and thefixture. Such fixtures can be configured as troffers, cove or othertypes of luminaires. In contrast to the modular combination of afluorescent tube with a pair of tube receiver sockets, the exampleluminaire can be integrally formed. Luminaires according to this examplemay be configured for operative coupling with a suitable fixture in amodular or integral fashion.

Further to the foregoing described embodiments, FIGS. 45A-49C show ahollow luminaire 4500 that is designed to provide a rotationallysymmetric intensity profile. Luminaire 4500 includes a housing 4512 witha cooler 4517, a cluster 4510 of LEEs and a collector 4520. Luminaire4500 may be referred to as a down light. Collector 4520 is a hollowelement that includes tapered surfaces extending around cluster 4510. Afirst reflector 4530 is positioned in the path of light emitted from theLEEs and collimated by collector 4520. First reflector 4530 includes aconical, reflective surface 4532 having a v-shaped cross section.Luminaire 4500 has a rotational symmetry axis, which insects the apex ofthe conical, reflective surface 4532 of the first reflector 4530.Luminaire 4500 further includes a rotationally symmetric secondaryreflector 4540 positioned to receive light reflected from firstreflector 4530 and redirect the light to the target surface through awindow 4539. The window 4539 may be transparent, translucent orotherwise configured. The secondary reflector 4540 has a convex profile.First reflector is attached to window 4539. Mounting elements secure andposition window 4539 and thereby first reflector 4530 relative tosecondary reflector 4540 at a specified distance from the LEEs and thecollector 4520.

FIG. 46A illustrates a perspective view of the secondary reflector 4540.FIG. 46B illustrates a perspective view of a secondary reflector element4541 of the secondary reflector 4540. The secondary reflector 4540includes twelve secondary reflector elements 4541. The secondaryreflector 4540 may be formed as a whole or from a number of elements bydrawing, welding, soldering or other process of suitable metallic,plastic or other materials. FIG. 47 illustrates a perspective view ofone of many alternative forms 4547 of a secondary reflector for theluminaire 4500. In contrast to the secondary reflector 4540, which hasdiscrete rotational symmetry, the secondary reflector of FIG. 47 hascontinuous rotational symmetry about its optical axis.

The optical components of luminaire 4500 can be produced from a varietyof materials. For example, the components can be produced from a metal,such as aluminum, or from a plastic coated with a reflective material.

In general, the intensity distribution provided by luminaire 4500depends, inter alia, on the geometry of collector 4500, the geometry offirst reflector 4530 and secondary reflector 4540, and distances betweencomponents of the luminaire 4500, and these parameters can be varied asdesired to provide an intensity distribution suitable for theluminaire's intended purpose. For example, the angular width of lobes inthe intensity distribution in cross-section depends on the degree ofcollimation provided by collector 4530 and the amount by whichreflectors 4530 and 4540 introduce divergence or convergence to thelight. The intensity distribution illustrated in FIG. 48 at least inpart depends on the configuration of and relative orientation of thereflective surfaces. In this plot, 0° corresponds to the positivez-direction.

FIGS. 49A-49C illustrate plots of the simulated intensity distributionthat is generated by the luminaire 4500. Depending on the specificconfiguration, such a luminaire may be useful for various applicationsincluding commercial or residential lighting. FIG. 49A shows a contourplot of the illuminance across the work surface, FIG. 49B shows a plotof illuminance (in lux) vs. Y position (in mm) at X=0, and FIG. 49Cshows a plot of illuminance (in lux) vs. X position.

Luminaire systems can include an extended source, e.g., a light bulb ora tube, a reflector and housing—such as fluorescent troffer or pendant.The source can provide a raw flux source, while the reflector andhousing can provide a system for supporting, conditioning, andredirecting light flux from the source to the work surface. Thesefixtures are powered directly from line voltage—such as in the case of adesk lamp—or a power transforming ballast as in the case of afluorescent ceiling troffer.

Devices described in this specification may be configured to use lightflux originating from a primary source of known dimensional, geometric,brightness and uniformity characteristics, and a secondaryreflector/refractor/combination optic to output a specified radiationpattern. The secondary optic can redistribute the source flux's“phase-space” to a new phase-space of prescribed dimensional extent andangular divergence (e.g., directional cosines) while maintaining asubstantially uniform intensity from the secondary optic. These devicescan provide uniform illumination of the work surface, efficient energyconversion from the light source of the devices to the work surface, anduniform and/or glare-free intensity from the fixture itself when viewedfrom the work surface. Additionally, these devices can provideglare-free intensity characteristics while maintaining efficiency anddirectionality in flux redirection.

Other embodiments are in the following claims.

What is claimed is:
 1. An illumination system, comprising: a pluralityof illumination devices, each illumination device comprising: aplurality of light-emitting elements (LEEs) arranged along acorresponding first axis; an optical extractor extending along acorresponding longitudinal axis parallel to the first axis; and a lightguide positioned to receive at a first end of the light guide lightemitted by the LEEs and guide it to a second end of the light guide,wherein the optical extractor is optically coupled to the light guide atthe second end, the optical extractor being shaped to redirect the lightguided by the light guide into a range of angles on either side of thelight guide, wherein the illumination devices are connected to eachother to form a polygon such that the longitudinal axes of the connectedmodules lie in a common plane.
 2. The illumination system of claim 1,wherein the polygon has a maximum dimension less than 2 feet.
 3. Theillumination system of claim 1, wherein the polygon is a quadrilateral.4. The illumination system of claim 1, wherein the polygon comprisesfour or more illumination devices.
 5. The illumination system of claim1, wherein the optical extractor is shaped to redirect light intodifferent ranges of angles on opposing sides of the light guide.
 6. Theillumination system of claim 1, wherein the optical extractor comprisesa first optical interface positioned to receive the light from the lightguide and reflect the light either side of the light guide.
 7. Theillumination system of claim 6, wherein for a cross-sectional plane, thefirst optical interface has a shape that comprises a vertex.
 8. Theillumination system of claim 6, wherein the optical extractor furthercomprises a second optical interface positioned in the path of the lightreflected by the first optical interface and configured to transmit thelight into the range of angles.
 9. The illumination system of claim 8,wherein for a cross-sectional plane, the second interface has a portionhaving an arcuate shape.
 10. The illumination system of claim 9, whereinthe arcuate portion has a constant radius of curvature.
 11. Theillumination system of claim 1, wherein each illumination device fromamong the plurality of illumination devices further comprises one ormore collectors arranged to receive light emitted by the LEEs and shapedto provide, to the first end of the light guide, light having adivergence smaller than a divergence of the light received from theLEEs.
 12. The illumination system of claim 1, wherein each of theplurality of LEEs of each illumination device comprises a light-emittingdiode.